Kelly is playing the enigmatic DCI Joanne Davidson in the sixth series of Jed Mercurio's hit BBC drama.
Keeley Hawes' new ITV drama stirred up plenty of mystery and intrigue after debuting on Sunday night.
It focuses on the investigation into the "honour killing" of Banaz Mahmod in 2006.
The BBC drama about MI5 spies was one of the most popular and enduring dramas of the 00s.
The Bodyguard star will appear in a new two-part series about the real-life murder of Banaz Mahmod.
“You need a big profile to be able to stand up for yourself."
Traitors will air next month.
"We’re looking forward to what the reaction will be on Sunday night."
We still can't believe it.