Bodyguard fans will finally learn the identity of the killer in one of the biggest TV whodunits of the year when the political thriller comes to its conclusion on Sunday night.
Audiences have been gripped by the series about controversial Home Secretary Julia Montague, played by Keeley Hawes, and her PTSD-suffering protection officer David Budd, played by Richard Madden.
The drama, penned by Line Of Duty creator Jed Mercurio, centres around Afghanistan war veteran Budd and his personal battles, and Montague, whose decision to hand the investigation of recent terror events to the Security Service ruffles feathers.
She is also widely criticised for pushing a new counter-terrorism bill through Parliament, which would give the security services the ability for mass surveillance.
Fans are waiting eagerly to find out who was behind the bomb that killed her during a high-profile speech in a surprise twist, and have watched as Budd tries to unravel the mystery around her death.
However, in a trailer for the final episode – which will last for an extended 75 minutes – Budd appears to be at the centre of the manhunt himself.
There has also been speculation that Montague may still be alive, fuelled by Mercurio himself.
The highly anticipated final episode is likely to attract one of the biggest TV audiences for a drama series this decade, as the smash hit thriller has seen a steady increase in viewers since it began in late August.
The latest available figures are for episode four (shown on September 9), which had a consolidated audience of 11.1 million.
This makes Bodyguard the eighth most-watched drama of the decade, in a list that also contains blockbusters such as Doctor Who and Sherlock.
Bodyguard will come to a conclusion at 9pm on Sunday on BBC One.