Darius Diddel is a brain cell living in the head of a schoolboy called Sebastian who lives in England and, in his final primary school year, is preparing for his transition to the secondary school. One morning Darius is woken up - unwillingly - by a loud noise. “The information storage is full!” the brain cells from the Information Sortation Department are shouting. Only a few hours are left till Sebastian wakes up and the information storage bursts. Will Darius be able to find a way in time to prevent this?