The actor, who is well known for his role as the manipulative Littlefinger, looks almost unrecognisable as he transforms into a gangster.
He can be seen without his Game of Thrones robes and signature goatee beard as he dons a 1940s-style suit.
Aidan can be seen dressed in a white shirt and grey blazer, which is layered underneath a thick brown coat.
Completing his new look, the star sports a matching brown trilby and is pictured loading a gun and pointing it at an unknown victim.
It’s not just Aidan’s clothing which is very different.
The star has ditched his cropped silvery locks in favour of wispy brunette curls, which fall to his shoulders.
The first look at the new series shows Thomas Shelby (played by Cillian Murphy) gather his family for a meeting despite having them locked up in prison at the end of season three.
In the one-minute-clip the Peaky Blinders can be seen moving back to Small Heath to reclaim their territory from new rivals, which may include Aidan’s character.
There are also fears for Aunt Polly (Helen McCrory), who is pictured walking towards a rope noose as she faces the death penalty.
Peaky Blinders returns to BBC Two later this year.
