The highly-anticipated finale of political thriller Bodyguard will leave viewers "deeply" satisfied, one of its stars has said.
Stuart Bowman, who plays Director General of the Security Service (MI5) Stephen Hunter-Dunn in the BBC One series, said that the sixth and final episode ties up all the loose ends involving Home Secretary Julia Montague's supposed death.
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He has also teased that "extraordinary things happen" in the climactic episode, and has hinted that there may be scope for a second season.
Audiences learned that Montague (Keeley Hawes) had been killed after an explosion during a high profile speech in a surprise twist, but some have since speculated that she may be alive.
Viewers have watched as her protection officer and lover David Budd (Richard Madden) tries to unravel the mystery around her death, but in a trailer for the last episode, he appears to be at the centre of the manhunt himself.
Bowman told BBC Two's Victoria Derbyshire that the many questions posed in the penultimate episode will be resolved, and that everything is "tied up".
He said: "The last episode is genius, in that everything kind of comes together, I don't think there is anything that is (left) unsatisfied.
"I had a look at the last episode a couple of days ago, and it's deeply satisfying, it's fabulous ... Extraordinary things happen."
Bowman said he has a "window" open to get back to filming on a possible second series, although has not signed anything, but that he would be "amazed if there wasn't" another season.
He added, referring to the drama's creator: "It's Jed Mercurio, anything could happen."
Mercurio, who also created Line Of Duty, has himself teased the ending, hinting that Montague might be alive.
He has also been vocal in defending the programme against critics who suggest it is not true to life.
Bowman said: "I trust Jed implicitly on this, and clearly his reaction shows how much he cares and how much attention he has paid towards these things, and I think he's been insulted by people saying that hasn't happened, when it completely has."
Bowman's character Hunter-Dunn has been at odds with Commander Anne Sampson, Head of the Metropolitan Police's Counter Terrorism Command (Gina McKee) throughout the series, which has centred around Montague's controversial politics and her decision to hand the investigation of recent terror events to the Security Service.
But viewers will have to wait until Sunday's episode to find out whether Hunter-Dunn or Sampson are involved in Montague's demise, whether it could be Budd, or even if she is still alive.
The thriller has been a ratings hit for BBC One and has been the biggest drama launch for the channel in a decade.
The most recent episode pulled in eight million viewers in the overnight ratings, peaking at 8.3 million.
The series will come to a conclusion in an extended 75-minute episode on Sunday at 9pm.