Newt Scamander’s brother (played by Callum Turner) was teased during the first Fantastic Beasts film, although you’d be forgiven for missing it.
It seems that Theseus’ name precedes him — when Newt appears before representatives of the International Confederation of Wizards during the first film, they recognise his surname because of Theseus, a famous war hero.
However, Theseus is also in a relationship with Leta Lestrange (played by Zoe Kravitz), Newt’s love interest during their time at Hogwarts — meaning both brothers are embroiled in a love triangle.
In an interview with Entertainment Weekly, Redmayne said: “[Leta’s] somebody who has touched [Newt] hugely and at the beginning of this film you realise she’s in a relationship with his brother so, of course, that comes with great complications.”
Who is Theseus Scamander actor Callum Turner?
Eddie Redmayne and Callum Turner attend Comic Con in July 2018 (Getty)
The London-born actor, 28, Turner is probably best known known for his roles as Bill Rohan in the film Queen and Country and as Eli in Jack Thorne’s E4 series Glue.