A peaceful island turns into a prison when one morning a group of armed activists take the entire population of the picturesque, isolated town off the coast of Brittany hostage. They are highly organized, but their motives remain secret. There is only one thing that Alpha, their leader, has not taken into account: five passengers from the shuttle that connects the island to the mainland manage to escape and hide. As the islanders face this extraordinary, deadly situation, secrets and sources of conflict emerge.