Martin (Cillian Murphy of 28 DAYS LATER) and Kate (Thandie Newton of THE CHRONICLES OF RIDDICK) , who are having some serious troubles with their marriage, return to an isolated island cottage in hopes of reconciling. There's definitely a big rift between the two and she simply wants to write in her diary instead of talking to her husband. Then, their generator stops working. They call, on the radio,for the handyman to come out but there's no answer. Then, while walking around the island, find an unconscious injured soldier. They bring him back to the cottage. When he awakens he tells them that an apocalyptic virus is killing everyone in Europe and that they have to barricade themselves inside. They can't leave or let anyone inside without risk of getting infected. The disease is 100% fatal. But the soldier begins to act strangely and the couple questions if there's really a threat at all--or if the guy is simply crazy and keeping them prisoner.
For a movie with only several characters and one main location it never gets boring or makes you want to fast-forward the film, primarily to the credit of the writing and the actors. RETREAT is along the lines of DEAD CALM and keeps you guessing as to what's going on until the end.