- "F***ing Spectacular!"
- ― Merlin when Valentine's chips were activated.
Kingsman: The Secret Service
In 1997, Merlin along with Galahad, were on a training mission in the Middle East with trainees Lee Unwin and James Spencer (candidates for the position of Lancelot at the Kingsman Agency), when the soldier they held captive pulled a grenade pin, Lee jumped onto the soldier covering the explosion, and saving his surrounding team.
17 years later, Merlin along with Harry and the other members of Kingsman, were tasked with finding a replacement Lancelot when Spencer was killed during a failed rescue mission of Professor James Arnold in Argentina.
Once Merlin learned of Harry's presumed death, he sent Eggsy to Richmond Valentine's headquarters via a Kingsman Jet. When Valentine's henchmen had the jet in which Merlin was hiding and the corridor where Eggsy stood, he was forced to activate the microchips (which Valentine had planted in everyone who had agreed with his plans as a safety measure) causing everyone of Valentine's henchmen and business partner's heads to explode.
Merlin becomes the head of Kingsman when the headquarters is attacked by ICBMs. Along with Eggsy Unwin, executes the 'Kingsman Doomsday Protocol', upon which the two discover a bottle of Kentucky bourbon in a wine shop vault, with the 'K' of Kentucky etched into the bottle, being the logo of the Kingsman agency, leading the two of them to Kentucky and the headquarters of Statesman.
In Cambodia, when invading Poppy Land, Eggsy accidentally steps on one of her landmines. Merlin sprays a canister which freezes the detonation temporarily. However, once Eggsy lifts his foot off the mine, Merlin suddenly steps on it. The effect of the spray by that point was diminishing and the canister was empty. Merlin decides to sacrifice himself to save both Eggsy and Hart's lives while killing a few of Poppy's soldiers, and sung 'Take me Home, Country Roads' before his death.
- Kingsman - Teammates
- Richmond Valentine
- Charles "Charlie" Hesketh - Former Student
- Chester King/Arthur - Former Leader and Ally, turned Enemy
- Poppy Adams
- Merlin's real name is Hamish. It is revealed in The Golden Circle official novelization.
- Merlin's glasses have a correction, as he wears them all the time.
- Merlin seems to have a liking towards country music, as the song he sung as a distraction before he died, was "Take Me Home, Country Roads" and his favorite singer is John Denver.
- Merlin seems to be right-handed, even if he doesn't wear a Kingsman ring we can notice he wears all his weapons in his right hand.
- Even if nothing is said about his sexuality in the movies, Matthew Vaughn said in an interview he intends Merlin to come out as gay.
- His death is very similar to that of Malcolm Merlyn in the TV series Arrow; Both step on a land mine in someone else's place, and then set it off, blowing themselves up along with multiple enemies. Their names are also similar.