Spoiler warning: Spoilers for Season 2 only; no final-season outcomes.
Gus survives Abbot’s arrow, while Aimee dies from the Sick. Sweet Tooth ends its second season with Gus, Jepperd, Wendy and Becky leaving for Alaska to find Birdie, carrying losses the victory at Yellowstone cannot reverse.
What does the battle resolve?
The hybrids escape captivity, and Abbot’s attack is stopped. His violence continues even after he is trampled, when he wounds Gus before falling again.
Gus’s survival is confirmed through the care he receives afterward. It is not necessary to invent an unseen immunity to explain why the story can continue with him.
Aimee’s death provides the different outcome the fight cannot prevent. She refuses treatment made at the expense of hybrid children, preserving that commitment even when the cost is her own life.
Why does Dr. Singh lose Rani?
His pursuit of a cure has become more consuming than the relationship he says he wants to save. When escape becomes possible, he prioritizes his research while Rani leaves.
The separation exposes the difference between invoking another person’s survival and remaining responsive to that person’s wishes. Rani is no longer simply the reason he can cite to justify whatever happens in the laboratory.
His continued interest in Gus therefore carries the danger of that unresolved obsession, not only the hope attached to scientific work.
Why go to Alaska?
Birdie’s recording gives Gus a larger understanding of her work and his place in it. Finding her now means helping address the Sick as well as meeting the mother he has sought.
The final departure is a new objective, not an accomplished cure. The season does not show the group reaching a final answer to the epidemic.
Zhang’s closing scene likewise establishes that another powerful figure intends to act, without revealing every detail of what she keeps caged.
The children have gained freedom from one captor while entering a wider conflict. Their makeshift family goes north because surviving together has created both the support and the responsibility to attempt something beyond escape.
Sources: official ending breakdown.