Marcellus critiques human platitudes like “Ignorance is bliss,” contrasting them with his own reality of captivity. He recounts how learning sustains him: solving enrichment puzzles from Terry, opening his tank and the pump-room door, and calculating how far he can venture without suffering consequences. Knowledge, he says, offers a temporary abatement of misery.

He argues that ignorance endangers all creatures, illustrating with a herring unaware of a lurking shark. Turning to humans, Marcellus describes a father praising his son’s athletic potential, then reveals the man is not biologically related to the boy. He supports this with observed physical and behavioral markers—nose shape, eye shade, earlobe position, voice inflection, and gait—predicting a future rupture.

Marcellus then applies the same scrutiny at the aquarium. He notes that Tova and the new sanitation worker walk alike and share a low heart-shaped cheek dimple, green-gold eye flecks, and a similar toneless hum while mopping. Acknowledging Tova’s long grief for her only child who died thirty years ago, he nonetheless asserts the evidence is clear: the young man is Tova’s direct descendant. Fatigued by the effort, he ends his reflection.