Line Of Duty has a lot of answers to deliver in Sunday night's nail-biting finale.
From the secret identity of H to Steve Arnott's prescription drug problem and who killed Gail Veller, there have been a lot of mysteries which have been left unsolved.
The latest dramatic trailer vowed: "Every investigation has led to this."
Already Martin Compston, who plays Steve, has promised the show will deliver "a lot of big answers" in the last episode of series six.
The actor praised the "great script" on his Twitter and teased the finale in the podcast: "If it goes down well it might be the perfect ending."
Speaking on the Shrine Of Duty podcast, he said: "There are a lot of pay-offs coming this Sunday.
"There are a lot of big answers that are coming, and I think it's deserved."
On the Jonathan Ross sofa, Martin claimed fans were "getting close" with their "wild theories".
Here is everything we want to find out tonight...
Who is H?
The mystery of "H" or who is also known as the "Fourth Man" has been the best-kept secret on the show.
No one knows whether the shadowy leader of the OCG (Organised Crime Group) is a man or a woman.
Ted Hastings has been under the microscope after he misspelt definitely 'definately', just like the messages sent by the secretive OCG member.
Suspicions have been building as the gaffer has done little to convince the audience of his innocence when he handed £50,000 to John Corbett's widow Steph.
How will Ted manage to explain giving away the £50,000?
Question marks remain over the time where Ted visited Lee Banks behind bars.
Their meeting was off-screen and their conversation remains a mystery to fans.
In the latest series, Lee had Steve believe Ted told the jailbird about Corbett's identity as an undercover cop.
If Ted didn't reveal Corbett's real job, what was he really talking to Lee about?
Corbett was brutally murdered when his true identity as a police officer was blown.
Is Ted bent?
Other possibilities for H include: Patricia Carmichael, Philip Osborne, Marcus Thurwell.
What will happen with Steve Arnott's drug problem?
Behind the scenes of his job, Steve has been battling his own personal demons.
The detective has been dosing up and self-medicating to relieve his chronic back pain.
Fans have been watching in sympathy as Steve was left in severe pain and was unable to perform in the bedroom as a result of his injury.
Tensions have been running high as Steve only has days to check in with HR to make his appointment with occupational health.
In an intimate conversation with widow Steph, the ambitious AC-12 officer revealed he couldn't seek help for the nerve damage without putting the future of his career in jeopardy.
Who killed Gail Vella?
Gail Veller was brutally murdered to stop her investigation into police links to organised crime coming to light.
The OCG were tangled up in her murder because the writer had been working on exposing the corruption within the police world.
Carl Banks was overheard bragging in a pub about murdering the broadcast journalist before he was killed.
Previously, his brother Lee Banks had given a false interview to Gail to try and find out exactly what she knew about the workings of the police corruption.
The identity of who had Gail murdered has yet to be revealed.
What happened to Carly Kirk?
Carly Kirk disappeared from the world of Line Of Duty without a trace.
Still a missing person, the mystery of her whereabouts has gone unanswered since she was last seen in series two.
Four series later, it raises the question could Carly be making a return for the finale of season six, and where did she really end up?
The schoolgirl was groomed into working for the OCG by paedophile Tommy Hunter.
Teen Carly was ordered to get DCC Mike Dryden into a compromising position so the OCG could secretly take photographs of him to use as blackmail leverage.
The plan failed when Lindsay Denton caught the pair in his car.
Hunter turned his violence towards Carly but she made a great escape.
She was seen boarding a ferry before completely vanishing into thin air.
What will happen with Jackie's body?
Jackie Laverty's skeleton has been hidden for years.
The shady property developer, who was having an affair with DCI Tony Gates and using her business to launder drug money for the OCG, was killed off in series one.
All these years later, AC-12 have finally discovered the freezer with traces of her blood.
Jackie's body had been stashed in vulnerable Terry Boyle's freezer by the OCG.
His freezer was absent from his home when Terry, who has Downs Syndrome, was stitched up by the OCG for Gail's murder in series six.
Yet the same kitchen appliance turned up at a scrapyard, empty, with a blood deposit which reveals the link to Jackie.
Upon the discovery, Ted said: "This is everything."
*Line Of Duty ends tonight at 9pm on BBC1
