Cynthia Littleton Business Editor Here we are at the precipice of an uncertain yet familiar place. The question of whether the TV and film industry will be shut down by labor action will be answered one way or another by the time Monday ends on the West Coast. In broad strokes, the Writers Guild of America and Alliance of Motion Picture and Television Producers face one of three basic outcomes as the WGA contract expires at midnight PST. Behind Door No. 1 – the sides reach a tentative agreement. Door No. 2 — they agree on a short-term extension, which is unlikely but could be anything from 12 hours to 12 days, or more. Door No. 3 – the talks are called off by one side or the other — or both — and picketing ensues in Los Angeles and New York on May 2.