They don't see him, but he's there. A stranger is watching... plotting... planning... and anticipating every move they make. Then he strikes. He imprisons a little girl and a famous reporter in the dank maze of tunnels beneath New York's Grand Central Station. The kidnapper is a remorseless psychopath who wants to collect a ransom, then murder his captives. His victims' only hope is their own wits -- and the aid of the dazed and desperate homeless people who roam this urban netherworld.