The peaceful planet Aneth was once at war with the mighty Skonnon empire. Now the Skonnon ships have returned to the skies of Aneth, demanding tribute. But as the final consignment is being taken to Skonnos, an accident forces the ship off course. The Doctor decides that the TARDIS is in need of an overhaul, and after materialising in deep space, dismantles most of the ships key circuitry, immbolising the time/space machine. Nearby is the stricken Skonnon spacecraft, and both shops are seemingly caught in a gravity field that could destroy them.