Susie asks Calvin what he's doing. Calvin shushes her quiet. He and Hobbes are having a water fight. Susie asks if she can play. Calvin scoffs at her saying war is a manly art. She supposes anything that idiotic must have to be. She asks if she can play or not. Calvin thinks she might prefer making smart remarks.

Susie again asks Calvin if she can join their water fight. She has her own water pistol at home. Calvin says it's alright, but she'll have to fight against both Calvin and Hobbes. Susie happily runs off saying she can beat him and his stuffed tiger any day. Calvin tells Hobbes that Susie is going to join them. Hobbes is wearing a pair of trunks and thinks girls flip for guys in Jams.

Susie comes over with her water gun. She sees Hobbes and thinks he's cute wearing his Jams. She gives him a squeeze. Calvin tells her to quit it and to go around the house to count till 50. Then, they'll start. Calvin scolds Hobbes for his Jams. He reminds him they're at war. Hobbes, with a big smile on his face, tells Calvin he's just jealous. Hobbes says Susie is a babe.

Calvin lays out the strategy to Hobbes. They'll split up with one of them going around the house in each direction. Calvin will draw Susie's fire, then Hobbes will sneak up from behind and hit her with a water balloon. Susie sneaks around the house, finding Hobbes sitting there with a water balloon. She thanks him for the water balloon and for being a great double agent.

Calvin charges Susie, squirting her with his water pistol. He stops when he notices she has Hobbes' water balloon. BLOOSH! Calvin gets smacked with the balloon. A dripping Calvin promises Hobbes he'll hang for this and calls him a traitor. Hobbes defends himself by declaring he's easily wiled by a woman in a swimsuit.

Calvin continues to complain to Hobbes, who is standing with arms crossed and a stern look on his face. Calvin says his best friend betrayed him, and he got soaked with his teammate's own water balloon. Calvin calls him a Benedict Arnold. Hobbes says he'd do it again. Susie likes his Jams. Calvin tells him not to talk to him. Hobbes sticks his tongue out at Calvin and says "Promises, promises". Susie walks over to Calvin, who is lying on the ground with Hobbes lying on top of him. Calvin tells Susie to get the traitor off of him, and that he cheats when he fights, too.