Jo Ann faced Benny Little, who was swinging his bat slowly, and threw the ball. Benny Little struck at the ball but it whizzed past him and thudded into Wicky Wickham's hands. "Strike three! Batter out!" cried the umpire, and Benny Little threw down his bat in disgust and walked away. Joe Bates, another of the Camp Mondega boys, walked up to the plate and faced Jo Ann, and Wicky Wickham crouched down in the approved catcher's position behind the plate. As Jo Ann made ready to throw the ball, Erne, one of the smaller of the Camp Minnedawa girls, came running. "Jo Ann! Jo Ann!" she cried. She was greatly excited and Jo Ann turned to the umpire for permission to see what the eager child wanted to tell her. "Time out," said the umpire and Jo Ann walked to the edge of the diamond. "What's the matter, Erne?" Jo Ann asked. "Why -- why --" gasped the small Erne, "the museum is robbed. There isn't a thing left in it. Everything is gone." Instinctively Jo Ann looked at redheaded Tommy Bassick who had for so long been the pest of her life, for this was just the sort of trick he would play on Camp Minnedawa. But he was already coming toward her, running across the diamond from the Camp Mondega bench, casting aside his favorite bat as he came. Others were coming, too, but Tommy reached Jo Ann first, and he thrust out a fist and touched Jo Ann's hand. "Knuckle to knuckle and hand to hand," he said. "One for all, together we stand," and he added hastily, "Play ball, Jo Ann." "Knuckle to knuckle," Jo Ann answered, looking him in the eye for an instant, and then she spoke to the others who were now crowding around her and Effie. "It's our museum," she said. "It has been looted. I'll attend to that later. Play ball now." "But, Jo Ann," said Bumpy -- who was Miss Bumpus, the director of Camp Minnedawa -- "hadn't you better go and see what damage has been done?" Again Jo Ann looked at Tommy Bassick but Tommy was standing by Ted Spence. The two boys had their doubled fists together and Tommy shook his head ever so slightly. Only for an instant did Jo Ann hesitate. "If the things are gone, they're gone, Miss Bumpus," Jo Ann said. "Won't it do if I see about it after the meet is over?" "Yes," Miss Bumpus agreed. "I'll go down and see what has been done." She called Miss Franz, leaving Miss Cooper in charge. "Undoubtedly one of the tricks of the Camp Mondega boys," said Miss Franz. "The little wretches don't forget the tricks Jo Ann played against them last year, and they probably know you made her curator of the museum this year." Jo Ann was already in the pitcher's box and the umpire called out "Play ball!" and the game went on. For over a month Jo Ann and Wicky Wickham had been practicing as pitcher and catcher, getting ready for the annual Field Day meet between Mondega and Minnedawa, the two camps that were almost side-by-side on Lake Lomas. Jo Ann, who captained the Minnedawa nine, was proud of her team, but a ball game depends on the pitcher, and Minnedawa had no adequate substitute for Jo Ann. Jo Ann was Minnedawa's only hope of beating Mondega. As she faced Joe Bates now she noticed he was a left-handed batter and she pitched the ball accordingly. "Strike one!" called the umpire as Joe Bates swung at the ball and missed. Joe Bates scowled. It was mortifying to have a girl pitch balls he could not hit. He reached for the next one and banged it straight into Jo Ann's hands. She tossed it to the first base. "Batter out!" called the umpire. "Who's up next? Batter up, Mondega." Tommy Bassick was the next man up and he went out on a fly to third base. No runs yet for Mondega, and now it was Minnedawa's turn at bat. Jo Ann walked to the plate and Tommy Bassick went to the pitcher's box. He threw his best trick ball but Jo Ann's bat found it and sent it ripping along the ground, and she slid for first base and reached it. She stole second, made third on a fumble of Joe Bates', and came home when Wicky hit a nice one between first and second bases. Jo Ann dropped on the Minnedawa bench, panting from her run. A few minutes later Wicky was put out at third base and came to sit on the bench beside Jo Ann and chat for a moment. "Hard luck," Jo Ann said. "Your foot wasn't an inch off the base. If I had been in your place I wouldn't have been out." "Why not?" demanded Wicky, instantly indignant. "Well, my foot is about an inch longer than yours, isn't it?" asked Jo Ann, laughing. Wicky laughed too. Jane Darrow had just hit the ball a resounding whack and was running for first base. She beat the ball to it and was safe on base. "Good girl, Jane!" Jo Ann shouted. "Get out there and coach her, Gladys," she ordered Gladys Carter. "Don't let her play too far off the base. That's her trouble, and Tommy Bassick throws a mean ball." The ball game was the final event of the Field Day and by mutual agreement counted five points in the day's total. Thus far, Camp Minnedawa was one point behind the boys' camp, and that it was not even more behind was due to Jo Ann. In the morning she had won the fancy dive and the hundred yard swim, and after lunch she had beaten Tommy Bassick in the running long jump and the running high jump as well as the hundred yard dash. Even Miss Bumpus had been pleased. "It does seem," she said to Miss Cooper, "that there are times when a tomboy is not altogether a nuisance in a camp." "But, my dear Miss Bumpus," said Miss Cooper, "Jo Ann is never a nuisance. Not this year at least. Not since we made her curator of the museum." "You mean birds' nests, I suppose," smiled Miss Bumpus. "I'll admit that Jo Ann is excellent when she is in the tops of trees." As a matter of fact, making Jo Ann curator of the camp museum had been Miss Cooper's idea. It could not be denied that in past years Jo Ann had been rather too tomboyish for comfort in the camp but Miss Cooper had the thought that the way to handle Jo Ann was to give her much to do rather than to try to keep her otherwise in control. And Miss Cooper seemed to have been right. In past years Jo Ann's one thought had appeared to be to plan some annoyance for Tommy Bassick, over at Camp Mondega, inciting Wicky and other girls to aid and abet her, and getting everybody into more or less trouble. The curatorship job seemed to have changed Jo Ann entirely. "Oh, Miss Cooper!" Jo Ann had exclaimed. "May I really be curator of the museum? I'll just love it!" And she had loved it. The museum, when Miss Cooper appointed Jo Ann to manage it, had been a most sad place. It occupied a small shack and inside were shelves on which the museum's treasures were displayed, and they were a most disreputable lot of treasures. Each specimen was supposed to be labeled but the labels were mostly off the specimens and the specimens all mixed and out of place. Or gone. There were a few dried mushrooms, mostly broken; a few specimens of various kinds of wood; a few pieces of rock; a skeleton of a squirrel's head, and a few birds' nests that were fallen to pieces and worthless. The museum, as Jo Ann said, was "a regular junk pile, mostly on the floor," but with her usual energy she set to work to correct this. With Wicky Wickham as her assistant she formed a "museum squad" of eight girls and threw out the damaged specimens, put new labels on the good ones, cleaned and scrubbed the shack and put everything in order. Then, heading her squad, she set about gathering new specimens to make the museum something worthwhile. She climbed trees, tramped the woods, gathered mosses and wild flowers and fungi, and her enthusiasm spread through Camp Minnedawa. Soon all the girls were bringing her specimens and asking, "Jo Ann, can this go in the museum?" and Miss Bumpus blessed the day that Miss Cooper had made Jo Ann curator. "We will remember this as 'museum year,' I think," Miss Bumpus said. "The girls were never so interested in the museum before." Between the museum and her preparation for the sports for Field Day, Jo Ann was indeed a busy person, but these were not the only reasons she neglected redheaded Tommy Bassick. As she sat on the bench watching her side play snappy ball, she also watched Tommy Bassick pitching for the Mondega nine. "Wicky," she asked, "you don't think Tommy Bassick could be a renegade, do you?" "Renegade? You mean a traitor?" asked Wicky. "You mean robbing the museum?" "That's what I was wondering," Jo Ann said. "You know I have done a lot of things to him, other years. I did think he meant it when we pledged ourselves to be the Four Musketeers and to be for each other instead of against each other, but you can't tell when a boy is taking anything seriously. He may have meant all the time to take the first chance to play a trick on me." "And just say he would be a Musketeer in order to have you feel safe?" Wicky asked. "Jo Ann, I don't believe anybody would be that mean. I don't believe Tommy Bassick would -- not even to play such a trick on you as emptying your museum. I just know that Ted Spence wouldn't." "Then who did rob my museum?" asked Jo Ann. "There are plenty of other boys at Camp Mondega," Wicky pointed out. "Them?" said Jo Ann scornfully. "A lot of little snips! They wouldn't dare. They're scared to death of Mr. Branch." "You can't always tell," said Wicky. "You were a 'little snip' the first year you came to Camp Minnedawa, Jo Ann, but you started right in doing things. What did Tommy say when he went up to you when Effie told you the museum had been robbed?" "He gave me our Four Musketeers knuckle touch," Jo Ann said, "and said our pledge -- 'knuckle to knuckle and hand to hand. One for all, together we stand.' I thought it was all right then, but now I don't know. Did you notice that he wasn't here for awhile when we were eating lunch?" "Why, he wasn't!" exclaimed Wicky. "And neither was Ted Spence! Jo Ann, you don't mean that they would do such a mean thing?" "I won't believe it until I have to," said Jo Ann, "but if they did steal the things out of my museum I'll never believe a boy again -- never!" What she meant was that she would never again have faith in any boy's word, for she had supposed that the Four Musketeer's pledge had been taken honestly by all four. For years, Jo Ann and Tommy Bassick had been relentless in causing each other trouble, and into their affrays they had drawn Wicky and Ted, but the time had come when Jo Ann had felt that the annoying battles should cease and in an hour of good feeling she had proposed that the four should stop quarreling and unite in amity. Tommy and Ted had seemed eager, and Jo Ann proposed that they call themselves the Four Musketeers and stand "One for all and all for one." Tommy himself had suggested the sign of union, a closed fist, and Jo Ann had thought up the rhyme "Knuckle to knuckle and hand to hand. One for all, together we stand." Solemnly with closed fists they had touched knuckle to knuckle. It was the pledge that they would stand together, if need be, against the world. "As soon as the game is over," said Wicky, "we'll talk to Mr. Tommy Bassick and Mr. Ted Spence. What was that?" The question was brought out by a low rumble and both girls turned to look across the lake. Over the eastern hills clouds were piling high in the sky. "It was thunder," Jo Ann said. "There's a storm coming." And indeed there was. As the ball game continued the clouds piled higher and higher and as the sixth inning ended with Camp Minnedawa 8 to Camp Mondega's 7, the wind came with a swoop of cold air, and huge drops fell. "Game called!" shouted the umpire. "Minnedawa wins." And he dashed for his coat and picked it up and ran. In an instant everyone was running, and before anyone reached shelter the rain was pelting down. Jo Ann was soaked before she reached her shack at Camp Minnedawa. She had had no time to say a word to Tommy Bassick. Wet as she was she knew she could not get any wetter and she ran down the hill to the museum shack and went inside. The specimens had been entirely removed. Not a thing remained on the shelves. In the middle of the floor stood the table that Jo Ann had called the "preparing table," where specimens had been put to be labeled or to dry -- mushrooms and such things -- and even the oilcloth cover of the table was gone. "How horrid! How awful!" a voice exclaimed, and Jo Ann turned to see Wicky standing beside her observing the desolation that had so recently been a well-arranged museum. "Jo Ann, what a shame!" "Yes," said Jo Ann. "And somebody will be sorry for this, Julia Wickham, or my name is not Jo Ann. They've taken everything, even my hummingbird nest. Why, even my Indian axe head. Everything!" "Did they leave any message?" Wicky asked, for usually the boys of Camp Mondega -- and Jo Ann, too, when she had made any such raid as this -- left a word of triumph, such as "Mondega wins!" or "Now will you be good!" "There was nothing here," said Jo Ann, "but, of course, Bumpy was here. She came right over as soon as Effie brought word. If there was a message left she may have taken it." "Well, honestly," said Wicky, "I think Bumpy ought to send for the police. When boys get to stealing everything out of a museum it's time they were arrested. When you think how you worked and worked, Jo Ann, to get everything together, and how everybody spent time this summer getting specimens, it is just too mean! Did you find any clues? Were there any footprints?" "There couldn't be any," said Jo Ann with a wry smile. "There was no dust on the floor to show footprints. I kept the floor too clean." "And no buttons with pieces of cloth clinging to them?" "We don't need any clues," Jo Ann said. "Who would take a lot of dried mushrooms and things like that except somebody from Camp Mondega? Just for spite, or to be smart. But, Wicky, I did think Tommy Bassick was going to play straight after we pledged." "We don't know it was Tommy yet," said Wicky. "Here, what's this?" She darted to a corner of the room and picked up a small brown object. "Only one of the dried mushrooms," she said. "I thought it might be a clue. But, come on, Jo Ann, there's no use standing here. We'll take our deaths standing around in these wet clothes. Let's go change them." "Yes," said Jo Ann reluctantly. "What do you suppose they did with all our specimens, Wicky? Dumped them into the lake?" "They may have." "Wait a minute. Why did they take the oilcloth off the table?" "To carry the specimens in?" asked Wicky. "They wouldn't take the oilcloth just for meanness. Please come on, Jo Ann. I'm awfully chilly." "I'll come," said Jo Ann. "I feel so -- well, I just feel awfully, Wicky! I did think, when we were willing to be friends with Tommy and Ted, and trusted them, and everything, and pledged to stand together always, that they might --" She had gone outside and had closed the door. The rain was still falling. Jo Ann stopped short in what she had been saying and bent down. A sodden piece of white cloth lay on the ground just outside the door. A heel, probably Bumpy's heel, had trod on it. Jo Ann bent and picked up the wet cloth. It was a handkerchief and she spread it open. Sewn close to one corner was a label, red letters on white, and the name on the label was "Thos. Bassick." "Oh!" exclaimed Jo Ann in something like a wail, and she handed the handkerchief to Wicky. "I guess that proves it." "That settles it," said Wicky. The two girls ran for their own shack and were soon out of their wet clothes and in dry ones. Jo Ann hung Tommy Bassick's handkerchief over the foot of her cot to dry. "What are you going to do about it, Jo Ann?" Wicky asked. "I don't know," said Jo Ann, "but it will be something that Tommy Bassick and Ted Spence will remember as long as they live. I can't think what it will be yet. I'll have to take time to think of something." "But why," asked Wicky, "do you think they did such a thing?" "Oh, don't ask me!" exclaimed Jo Ann. "They're boys, and that's why, I suppose. They just have to show how smart they can be." The door of the shack was open, facing away from the slant of the rain, and as Jo Ann turned to look out she saw Coopy coming toward them from headquarters. The energetic Miss Cooper was almost hidden by her rainproof coat and hat, but the girls knew her by her long stride. She came straight to Jo Ann's shack. "I won't come in," she said. "I'm dripping. Miss Bumpus wants you at headquarters immediately, Jo Ann. Have you rubbers and a raincoat? You'd better wrap up well." "Yes. What have I done now, Miss Cooper?" "Nothing this time. And you may come, too, Wicky." With that Miss Cooper turned and walked back toward headquarters, following the mudless cinder path. Jo Ann drew on her raincoat and slid on her rubbers. "You don't suppose Bumpy is going to take the museum away from you because of this, do you?" Wicky asked. "I don't see why she should," Jo Ann answered. "The door wasn't locked," Wicky suggested. "It never has been locked," said Jo Ann. "Bumpy takes the padlock off the day she comes to camp and the door is never locked again until the day she goes. She can't blame me for that. If she does, she won't be fair." But it was not about the door that Jo Ann was called to headquarters. She knew it was not that as soon as she stepped up onto the headquarters' veranda for, spread on two chairs, were two yellow slickers, and painted on the back of one were the letters "T. B." while on the other were the letters "T. S." "Jo Ann!" exclaimed Wicky in an excited whisper. "Bumpy has raised a row at Mondega and Mr. Branch has brought Tommy and Ted to apologize!" "They'd better!" declared Jo Ann, and she walked into the big hall of headquarters. Tommy and Ted were standing, and Miss Bumpus and Miss Cooper and Miss Franz were seated, and Tommy grinned. It was not the sheepish grin of a boy who has been sent to give an unwilling apology, however. "Tell her, Bassick," Miss Bumpus said. "Knuckle to knuckle," said Tommy, grinning more broadly at Jo Ann. Jo Ann pointedly ignored the fist that Tommy held out. "What's that, please?" asked Miss Bumpus. "It's a greeting we have at home in Greendale," Tommy said. "You wouldn't understand it but Jo Ann does all right, Miss Bumpus." "I did once," said Jo Ann. "I suppose you came to confess that you took the things out of my museum." "Yes, that's what I came for," Tommy said. "I took them -- Ted and I. We meant to tell you, but the rain came so suddenly, and everybody ran. We came as soon as we got the Mondega ball stuff out of the way. We had to see that that got back to the camp." "I don't think I want to hear anything about it," Jo Ann said. "I think it was just too mean of you, Tommy Bassick. I'll never believe a boy again -- never! And after our pledge, too." She turned to go, but Miss Cooper put a restraining hand on Jo Ann's arm. "I think you had better hear what he told us, Jo Ann," she said. "After all, you ought to give him a chance to explain." "Miss Cooper, I don't want to hear anything he has to say," declared Jo Ann. "We made a pledge to stand by each other -- Wicky and this Bassick boy and Ted Spence and I -- and not to annoy each other but to be like the Three Musketeers, only we'd be four, of course. And that was our pledge -- 'One for all, together we stand' -- and the first chance these boys got --" "The first chance they got," said Coopy with emphasis, "they saved your museum." "What do you mean?" Jo Ann asked, looking at Tommy and Ted with a new interest. "How did they save it?" "I've been waiting to tell you, haven't I?" asked Tommy. "Ted and I heard some of the Mondega boys, just before lunch this morning, saying that Mondega would win the ball game. They said the Fearless Five -- whoever they are -- were going to raid your museum, and that you would hear of it and be so excited you wouldn't be able to pitch the game. One of the small boys would hand you a note telling you the museum was wrecked and all your specimens destroyed." "You'd get the note just after you had pitched the first inning," Ted explained. "Tommy asked me what we could do, and I could think of only one thing. Tommy and I had to be in the ball game. We couldn't go back on Mondega and stand guard over your museum, but we remembered 'Knuckle to knuckle and hand to hand. One for all, together we stand,' and we did what we thought was the best thing." "We slipped away during lunch and took all your specimens out of the museum," Tommy said. "They're hidden under the museum floor. They're safe enough where we put them, all right." "We hadn't the slightest idea that you would hear of it until the ball game was over," Ted said. "How could we know it would be found out so soon?" "I was going to tell you, but the rain came and everybody ran," Tommy said. "So we came over as soon as we could to explain about it. We couldn't get here any quicker." "Oh!" said Jo Ann and her expression changed. "Why, that's all right then. I'm sorry that I didn't understand. I shouldn't have been so suspicious. But you must admit it did look queer." She hesitated just the fraction of a second and then she walked over to the place where Tommy stood waiting, and held out her fist. "Knuckle to knuckle," she said. "And hand to hand, Jo Ann," said Tommy, grinning. "One for all," Ted Spence said. "That's it," said Wicky. "Together we stand."