Upon arrival at the remote beach, young Bobby goes exploring out onto a precarious, rotting jetty high above the water. His foot gets stuck in a crack between boards. After Doug frees him, they start back, but part of the jetty collapses, and a wooden piling falls on Doug's leg, trapping him on the beach just as the tide starts coming in. Helen tries to lift the piling with their car jack, but it breaks. Doug sends her for a rope or help at a deserted gas station they stopped at earlier. He estimates they have four hours before he drowns in the rising surf.