Elizabeth Henstridge and Charlie Weber get a little more than they bargain for in Hallmark Movies & Mysteries’ Mystery Island.

The two actors will star in the flick with Kezia Burrows, Yimarapérez Royko, Henry Twohy, Francisco Labbe, Matthew Chambers, Andrés Morales, Melanie Martínez, and more.

Here’s the full summary for the movie: London Police psychiatrist Dr. Emilia Priestly (Henstridge) needs to take a relaxing break from her stressful job, so her wealthy friend, Baroness Jane Alcott (Burrows), invites her to Mystery Island, an immersive murder-mystery-themed resort hosting a special retreat for the original investors.

As the mystery game begins, tragedy strikes: John Murtaugh (Robert Getman) the resort’s reclusive founder, is murdered. The visitors are confined to the island as local detective Jason Trent (Weber) investigates the case.

Once Emilia proves her innocence, she makes use of her special skills to help Jason find the murderer. The lines between game and reality are blurred as they unravel the web of romance, revenge, and betrayal behind the resort, its guests, and its elusive founder.

Mystery Island premieres TONIGHT, September 29 at 9 p.m. on Hallmark Movies & Mysteries.

Psst, don’t forget to check out the full Countdown to Christmas lineup!