British actor Hugh Bonneville has signed on to voice a new character in the upcoming “Thomas & Friends” film, titled Thomas & Friends: Journey Beyond Sodor.

In the new film, Bonneville will play Merlin, an experimental engine that is like no other engine Thomas has seen before. Merlin also has a special power–all he has to do is say “invisibility on!” and shut his eyes and he is convinced that nobody can see him.

The upcoming, 70-minute special will be shown in more than 70 countries worldwide and will premiere in U.K. theaters, Aug. 25.