The TARDIS arrives on an alien planet: just the place for the Doctor to test out his pedal-copter! Whilst flying, one of the blades breaks and his grandchildren and he fly out of control, crashing on a rocky outcrop. As they crash they see Daleks. The Doctor, John and Gillian use the shattered pieces of rocks around them to attack the Daleks. The Doctor, John and Gillian use a large boulder to stop the Daleks from following them and use the Dalek's space craft to return to the TARDIS.