Marty and Speed are middle-aged San Francisco cabbies who hack to support their fading dream of making it as professional actors. Perpetually down on their luck, the friends find escape and camaraderie among their fellow drivers, playing cards and telling stories of backseat conquests, until one night when a dreaded "Signal 7" (driver's call for help) comes over the wire.

After she's been attacked in her apartment, Cathy starts reliving the event in her dreams. She seeks help at a sleep disorder research center, but in doing so she encounters some unexpected results.