On the longest day of the year, Erik, Arni and Ylva face their most disturbing challenge yet – and something is waiting in the dark.
At first, Erik thinks he’s just having a very bad day - but something is very off, and the day turns into a waking nightmare of his biggest fears. He realises it was just a dream… except for the horrible spectral horse standing over his bed than then sends him back to sleep. Slowly the Trio work out that the Skool has been targeted by Mares. Now everyone is trapped in a collective nightmare. As everyone falls prey to their worst fears, the Trio need to piece together the clues to work out how they can ever break out of this nightmare.