When Marco, Suzy and Jo arrive at the Schloss Montrosa, a castle full of magic, mystery and microchips, to stay with their secret scientist uncle Professor Egbert Able for their summer holidays, they very quickly get more than they bargained for! They don’t realise that the strange riddle they find in the Schloss library will lure them on a quest with a mission to save the Universe. There are many problems to be solved, not least to find their uncle who has been abducted by an evil Marzipan, and to find the last clue of the riddle – a silver horse. But have they both been hidden far from sight within a black hole? Eventually, the quest commences with a hair-raising journey full of shocking surprises. It leads them to a crazy world of aliens and monsters that almost brings about their undoing. Worse still, when they finally reach their goal in the city of Spondoola, they are imprisoned by its king, the vicious, greedy Spondoolix. The race is on to bring their uncle home in one piece, but have they underestimated who they’re up against..?