Line of Duty actor Tommy Jessop, who played Terry Boyle, has revealed he is "proud and honoured" to have been a part of the BBC police drama, created by Jed Mercurio.
He said he thought it was important people with learning disabilities are represented on stage on screen to demonstrate just how capable they really are.
"It really is a proud and quite an honour to be a part of it all," said Tommy, who is already being recognised in the street for his role.
Tommy only found out who H was at the end of the series like the rest of us - but correctly guessed it was DCI Ian Buckells - unlike most of the viewers.
He had to keep his part "top secret" for a whole year, and said his favourites scenes were the intense police interrogation scenes, "because I do like making people laugh and cry and shout at the TV screens", he said.
And while the lake scene, for which he had a body double, was "like living in a freezer" Tommy revealed his kind-hearted co stars really helped.
"To warm up, my highlight was Vicky McClure was giving me a nice warm hug," he said.
Asked what his favourite part was of starring on the show, Tommy said: "All of it!"
He continued: "It really is important to include people with learning disabilities of all ages to show what they truly are capable of, because I really do want people to believe in us.
"Because we really are different people with different skills and ambitions.
"And to quote a certain that I played nine years ago, called Hamlet, 'We fools of nature are wondrous too'," he said.
Asked how he got into into acting, Tommy explained: "It was through a BBC talent fund for disabled actors, I auditioned to be a part of it as well."
What's next for Tommy? He says it's "top secret"! Grilled on if he might even be heading to Hollywood soon, he teased: "No comment."
"I really am grateful to Jed for such a brilliant role, and mate crime really does happen because it can be hard to tell your story because people do not actually believe you.
"So keep talking and keep listening, and that means really listen to people."
Mate crime is defined by Mencap: 'When someone says they are your friend, but they do things that take advantage of you, like ask you for money a lot.
'A real friend does not need to be bought, and someone who takes your money, asks you to pay for lots of things, or makes you feel uncomfortable is not a true friend.'
