Arthur Darvill, who played a companion to the Doctor in BBC’s Doctor Who, is in final negotiations to join the cast of the WB’s untitled DC Arrow/Flash spinoff show.

The series’ cast already includes Brandon Routh as incredible shrinking hero The Atom (aka Ray Palmer), Wentworth Miller as Captain Cold, Dominic Purcell as Mick Rory and Victor Garber as Prof. Martin Stein among others.

Darvill will play a character titled the Traveler, a cocksure time-hopping adventurer. There was speculation that the hero could be time-jumping Booster Gold, but The Hollywood Reporter has confirmed the character is Rip Hunter, one of DC’s classic heroes created back in 1959 and the leader of a time-traveling group.

(Interestingly, his origin was redone so that he became the son Booster Gold, who was created in the mid-1980s.)

In fact, inside the WB the character is described as " a roguish time traveler who hides the strains of being responsible for history itself behind a facade of charm and wit."

Greg Berlanti, Marc Guggenheim and Andrew Kreisberg are writing and exec producing.

This will be the first American television work for Darvill, who can be seen on the current season of BBC’s crime drama Broadchurch.

He is repped by Independent Talent and Silver Lining Entertainment.

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Email: Borys.Kit@thr.com

Twitter: @borys_kit