With just about an hour of oxygen left in his diving tank, Jay must endure a series of increasingly agonizing ordeals as he searches for a way to escape his terrifying predicament. There's a nasty encounter with the giant squid's razor-sharp beak, exposure to corrosive stomach acid, and the ever-present threat of being crushed by the whale's constricting organs or suffocating on the toxic, unbreathable methane gas inside its body. Amid the visceral horror of Jay's ingestion, we learn more about his complicated relationship with Mitt, a harsh and often emotionally abusive man, through a series of flashbacks.

Eventually, the whale breaches the surface and Jay nearly manages to break free by climbing out of its open mouth. But he ends up tumbling back inside the whale as it dives deep down into the ocean, causing Jay's eardrums to explode and him to start to hallucinate from lack of oxygen and panic. It's then that Jay, believing he is likely going to die, begins hearing his late father's voice speaking to him through the whale. As the whale is attacked by orcas, saved by its own pod, and returns to the surface, Jay is forced to process his trauma, confront the guilt and grief he feels over not visiting his dad before he died, and come to the realization that the only way he's going to survive is by applying the tough-love diving lessons Mitt drilled into him as a child to his current situation.