When the evil Skelloids launch an attack upon the seventeen worlds of the Generios system, its peace-loving inhabitants face total destruction. So it is fortunate the fact that famous traveller with time and space known just as the physician is in the area, and doubly lucky that, with the help of his pretty youthful associate, Sally-Anne, he manages to defeat the deadly animals and save your day. But now it appears as though the Doctor¹s good luck has run out. Who’s the strange, curly-haired stranger who insists on causing trouble? What role does the feisty redhead Melanie play in his plan? And what possess they regarding the sinister alien cylinder getting close to Generios? A very important factor is certain: for the Doctor and Sally-Anne, there¹s deadly danger ahead…