In this flashback, Alex thinks back over a life shaped by following Tom, the older brother he idolizes. Alex copies Tom's interests, studies marine animals partly to stay close to him, and eventually follows Tom to the remote research base on Shearwater. Alex feels out of place among the more experienced scientists, but he becomes close to Raff. Lying together in the sun, they joke about Shearwater's haunted stories, imagine a future trip to Vancouver Island, and Alex tells Raff about humpbacks defending a gray whale calf, insisting that the whales act out of empathy.

When Hank announces that some researchers will remain on Shearwater for three extra months to help catalogue seeds in the vault, Alex sees the extension as a gift because it gives him more time with Raff. Tom agrees to stay because he has fallen in love with Naija, and Hank needs help. As conditions on the island worsen, Alex, Tom, and Naija live in the red field hut and spend long hours underground in the vault. Hank had once carefully monitored their well-being during the grim work, but that attention fades after Hank begins to change.

On Raff's eighteenth birthday, Alex decides to give Raff one good night away from the island's tensions. He plans for them to sleep together in the empty green field hut, even though the weather is turning and Tom explicitly warns that the storm is dangerous. Alex ignores the warning because he is focused on Raff, their limited time left on the island, and his desire to make the night special. Raff pilots the Zodiac through brutal weather to the hut, and the two of them settle in while the storm grows more violent around them.

In the night, Tom and Naija arrive to evacuate them because the hut is no longer safe. Alex and Raff leave first in their Zodiac, assuming Tom and Naija will follow in the second boat. As they pull away, Alex looks back and sees the green hut torn from its pylons and thrown into the sea. Convinced Tom is dying because of his decision, Alex throws himself into the water to try to save him, but Raff drags him back into the boat. Later, Dominic and Raff recover Tom and Naija's bodies, and Alex helps bury them without the ceremony he wishes he could give Tom. The loss leaves Alex certain that he killed his brother, and afterward he repeatedly goes to sit above the base, staring down at the fuel tanks.