Twice Under plot
"In a gamble with a madman you must win the game ...or lose your life."
Ed Chambers has left the horrors of Vietnam behind. Also the nightmare when a friend was buried alive in the gigantic network of tunnels in the Vietnam jungle. Ed now has a job as a shift manager in the Los Angeles sewer system. What he doesn't know is that his friend Daggat made it and wants revenge. He is determined to get rid of Ed Chambers. Daggat goes into hiding in the sewer labyrinth of the city and starts a real terrorist action. Ed's death is not enough for the distraught Daggat. He kidnaps Rick's girlfriend, Ed's son, and lures Rick into the sewers.