Callum Turner plays Theseus Scamander, older brother of Eddie Redmayne’s main character, Newt Scamander. Theseus is an Auror, and both brothers seemed to carry a torch for Zoë Kravitz’s Leta Lestrange. Theseus was engaged to Leta in Fantastic Beasts: The Crimes of Grindelwald, but she sacrificed herself and at least appeared to die. It’s not clear if we’ll see Leta again in any form. But Theseus will return. We last saw him at Hogwarts with Newt and Team Dumbledore, with Credence and Queenie at Nurmengard on Team Grindelwald.