A Scottish police sergeant (Edward Woodward) arrives on the remote island of Summerisle to investigate the disappearance of a local teenager. Staying in a room at the village pub, he becomes increasingly frustrated at the local's reluctance to help him in the case - and alarmed at the increasingly strange actions of the locals.

Sgt Howie meets with the Lord Summerisle (Lee) and finds out that they are all pagans. Convinced they have murdered the girl, he tries to leave on his sea-plane but finds it has been sabotaged.  He makes his way back to the island, and follows the main procession - disguised as one of the costumed performers.
  He gets past a possible decapitated-scene unscathed - but then spies the missing teenager and follows her into a cave.  He is led into a trap, and imprisoned inside of a giant statue made of wicker among with a load of other animals.
  Under the guidance of the island rulers, they set fire to the wicker man and sacrifice Sgt Howie to hope for a better harvest.