Margeret Atwood's Hag-Seed is a metafictional retelling of Shakespeare's The Tempest. Many elements of The Tempest are clearly recognizable (e.g. Felix is very obviously Prospero), while others have interesting twists (e.g. Felix's daughter is a combination of Miranda and Ariel -- and there are other characters who echo Miranda and Ariel as well).
But one iconic character seems to be missing. Where is Caliban?
There's no clear reference to a Caliban character (as we have with Felix/Prospero, Tony/Antonio, Lonny/Lorenzo...). Nor is there any character who seems to take on Caliban's narrative role (e.g., attempting to undermine Felix, threatening something dear to him) or any of his thematic elements (e.g. being warped and misshapen; being mistreated by Felix).
One could argue that the book simply isn't focused on that facet of the story (as, indeed, the book is focused on some elements of The Tempest and not others), but the book's very title is Hag-Seed, a direct reference to Caliban. This seems to suggest that elements of Caliban should be central to the story --
-- and if so, what and where are they?