Tiger Heat (Sigmund Brouwer's Sports Mystery Series: Baseball)

Since when do baseball players take their game off the field and into the sewer tunnels beneath the city streets? Just ask the last-place Tigers, a group of kids some say should be in reform school. They play paintball wars in the tunnels. But when a friend gets hurt, it's up to Jim McClosky to help his teammates solve the mystery and survive the tunnels.