Kelly Macdonald will star as the guest lead in the next series of Line Of Duty.
The Trainspotting star will play Detective Chief Inspector Joanne Davidson in the BBC One drama's sixth series, which will start filming next year.
Line Of Duty writer and showrunner Jed Mercurio said: "We're honoured that Kelly Macdonald will join Martin (Compston), Vicky (McClure) and Adrian (Dunbar) in Series 6 of Line Of Duty.
DCI Joanne Davidson will prove the most enigmatic adversary AC-12 have ever faced."
Mercurio tweeted: "Everyone involved in #LineofDuty is thrilled Kelly Macdonald is joining us for Series 6, playing AC-12's most enigmatic adversary yet."