Noggin's small son Knut goes with Noggin to watch a demonstration of Olaf the Lofty's latest invention. The demonstration ends with a loud explosion - which leads to a strange adventure.
Noggin asks his inventor, Olaf the Lofty, to remove the great stone which has mysteriously appeared outside his palace, but to everyone's surprise the stone disappears as strangely as it came - and brings disaster.
Noggin's son, Knut, has a strange dream and Olaf's invention falls into bad hands.
Noggin's old enemy Nogbad the Bad threatens the kingdom with Olaf's dangerous invention.
Noggin's son, Knut, falls into the power of Nogbad the Bad when the stone giants take him to Roundhead Valley.
Nogbad the Bad finds the sorcerer's sword and threatens the kingdom with destruction.