Mayday! Mayday! is the distress call given by pilot Lou Parker just before the small plane carrying Lou and his family is forced to make a crash landing in the high Sierras. With Lou trapped in the wreckage and his wife, Janice immobilized by a broken leg, young Allison and Mark Parker set out alone to find help. Unknown to the children or the airborne searchers, back at the crash site their injured mother is waging a desperate battle against a stream of fuel flowing from the wreckage toward her signal fire. The prospects of rescue become increasingly dim as Allison and Mark struggle to elude a pack of wild dogs and encounter a rattlesnake ready to strike.