During a winter holiday at the Swiss Hotel Sinestra, 11-year-old Ava finds herself wishing that her overprotective parents would just go away. The following morning at breakfast, all the adults have suddenly vanished. And so the party begins: the children can do anything they want! Led by a remarkably childish boy called Jonas, they get a little carried away and a dangerous situation arises causing the entire hotel to be shrouded in darkness. Ava and her new friends go on a quest to find their parents in the midst of a big snowstorm so they can celebrate Christmas together.