Closure, by Derin, reviewed by Chromatographic
Rereading this, I went: “Why did I not have this bookmarked before?” and then I went “Wait, I didn’t even leave this kudos?”
This fic is a joy to read for obscure character interactions. It’s set post-series: Cassie has a conversation with Esplin 9466.
And this is a conversation. It grasps the characters like a vine grasps a stone wall, gripping into the cracks that canon left us and opening them up to see what lies beneath the surface: Esplin, not just a general but the scholar and Andalite biologist that he was; Cassie, not just the moral center of the Animorphs and veterinary assistant but also a rather brutal killer.
You really get the sense that Cassie sees this as part of her penance: She will look after her old enemy not out of enmity or amity but out of some sense of duty towards him. Esplin is meanwhile baffled by that - that this child who fought him and killed could want to have such a conversation.
They both look for answers in this fic, perspective from the other side, and somehow they find themselves looking back.