3. Eve Myles
Another well-known reoccurrence, Eve Myles’ role as psychic maid Gwyneth in 2005’s The Unquiet Dead ended up scoring her a lead role as Gwen Cooper in Torchwood.
4. William Thomas
The veteran Welsh actor played scientist and Slitheen victim Mr Cleaver in Doctor Who, and returned to the Whoniverse to take the role of Gwen Cooper’s (Eve Myles) father in the adult spin-off.