EXCLUSIVE: ABC’s Once Upon A Time is heading to Camelot for its upcoming Season 5, and a couple of weeks ago the series found its King Arthur in Liam Garrigan. Now OUAT has inked deals for more recurring guest roles that will join him: Elliot Knight has been tapped to play Merlin, and Joana Metrass is set to play Guinevere. In addition, Andrew Jenkins has nabbed the guest role of Percival, one of Arthur’s most loyal knights.

The upcoming season will center on the Savior, Emma Swan (Jennifer Morrison), becoming the new Dark One, and the search for Merlin, who is the only one who can save her. The news comes ahead of the show’s annual shindig at Comic-Con, where the network usually tips off upcoming cast (the Frozen cast additions drove fans nuts in Ballroom 20 last year).

Season 5 of Once Upon A Time premieres September 27.

The UK-born Knight starred in the 2012 Sky1/Syfy series Sinbad, which lasted one season, and more recently appeared last season in multiple episodes of ABC’s How To Get Away With Murder. He is next up in the movie Take Down opposite Ed Westwick and Jeremy Sumpter. Knight is repped by ICM Partners, Affirmative Entertainment and Payne Management in the UK. Metrass, born in Portugal and working in the UK, is next up in Guy Ritchie’s The Man From U.N.C.L.E. She’s repped by Industry Entertainment and Jonathan Arun.

Jenkins recurred on AMC’s The Killing and now is doing the same on Fox’s Wayward Pines. He is repped by Global Creative|Station 3 and Red Management in Vancouver.