Whether he's playing Captain Cold or the Earth-X version of the same character, Citizen Cold, Wentworth Miller has proven himself to be a fan-favourite member of the Arrowverse, and brilliant in his role ever since his debut in 'The Flash'. Now, he's making yet another return, but this could be for the last time.

Wentworth Miller is making a return to 'The Flash'Wentworth Miller is making a return to 'The Flash'

Last time we saw Leo Snart, he was a part of 'Legends of Tomorrow', but decided to leave and return to Earth, enjoying life alongside his superhero boyfriend Ray Terrill, aka The Ray (Russell Tovey). It'd seem the call for help from Barry Allen (Grant Gustin) will prove to be too much however, and he'll leave his life of serenity once more to jump back into the action.

A synopsis released by The CW for upcoming episode 'Fury Rouge' (written by Jeff Hersh and Joshua V. Gilbert, and directed by Rachel Talalay) announced the comeback, and reads: "WENTWORTH MILLER RETURNS AS CITIZEN COLD — When Barry (Grant Gustin) needs help transporting a dangerous meta, he calls on a new friend for help – Leo Snart AKA Citizen Cold (guest star Wentworth Miller). Meanwhile, Cisco (Carlos Valdes) becomes suspicious of Harry (Tom Cavanagh)."

Exactly who the "dangerous meta" alluded to could be remains to be seen, but as The Thinker grows stronger and his plans for ultimate power gain ground, the work for the team at STAR Labs continues to grow. That's only going to be a heavier weight on all of them as Cisco's suspicions surrounding Harry grow.

Though Miller looks to only be back for a single episode, it's great to see the actor back on board following what the fan base thought would be a permanent exit from the Arrowverse. In keeping the door open for the actor, the opportunities for the future of 'The Flash' and its fellow CW shows grow exponentially. We can't wait to see what goes down!

More: Stephen Amell "Respects" Willa Holland's Decision To Leave 'Arrow'

'The Flash' continues on The CW in the US and Sky1 in the UK.