Jennifer, an Australian girl on the run from her past, turns up in Amsterdam and, in a desperate attempt to blend in, joins a coach-load of tourists on a tour of Holland's old windmills. When the bus breaks down in the middle of nowhere, she and the other tourists are forced to seek shelter in a disused shed beside a sinister windmill where a devil-worshiping miller once ground the bones of locals instead of grain. As members of the group start to disappear, Jennifer learns that they all have something in common – a shared secret that seems to mark them all for doom.
