During a winter holiday at the Swiss Hotel Sinestra, 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.