Josefine and her family arrive on the rustic, remote island of Årmandsø for their holiday break, but things get off to a bumpy - and bizarre - start.

While Josefine tries to help the wounded baby creature she found, her family's trip into the forest to find a Christmas tree ruffles some feathers.

Josefine grows suspicious when Karen invites her family for a visit and begins to question just how big of a secret the people of Årmandsø are hiding.

Josefine's family searches for her after she follows Kee-Ko into the forest, where the lurking terror that resides there will soon be revealed.

With the forest's security perimeter severely damaged, the elves begin to roam the island freely, armed with a thirst for blood - and revenge.

After Karen takes a drastic and dire step to try and appease the elves, everyone else must band together to save Josefine - and themselves.