Rats. Every Saturday, the group fights paintball wars with kids from other schools. These wars take place deep in the maze of tunnels that form the drainage system below the city streets. It's the one area in life in which the misfit Sewer Rats all seem to shine as they have never lost a match. When Carter, a new kid, attempts to join the group, Jim is more than confused by his friend Lisa's behavior. Jim cannot understand why Lisa is so hostile toward Carter, having him perform a crazy test to get into the group and later even setting him up to be attacked by a rival team in the tunnels. It is after this last incident that Jim and Micky discover that Lisa's father is Carter's step-father. She deeply resents the fact that Carter has her dad in his life while she does not. When Jim and Micky confront Lisa, she takes off into the tunnels. The two boys chase after her just as a storm erupts. Quickly, the tunnels begin to fill with water and a crumbling ceiling collapses. Lisa's foot becomes lodged under the rubble, and it is up to Jim and Micky to save her before the water rises above their heads.