The Doctor and Sarah arrive in London to find it deserted. The city has been evacuated as prehistoric monsters appear in the streets. While the Doctor works to discover who or what is bringing the dinosaurs to London, Sarah finds herself trapped on a spaceship that left Earth months ago travelling to a new world... Against the odds, the Doctor manages to trace the source of the dinosaurs. But will he and the Brigadier be in time to unmask the villains before Operation Golden Age changes the history of planet Earth and wipes out the whole of human civilisation? This novel is based on a Doctor Who story which was originally broadcast from 12 January–16 February 1974. Featuring the Third Doctor as played by Jon Pertwee with his companion Sarah Jane Smith and UNIT

In the year 2164, ten years after a cosmic storm and a plague which has wiped out much of Earth's population, the survivors are enslaved as miners by the Doctor's most evil enemies, the Daleks.

UNIT is called in when an important diplomat is attacked in his own home - by a man who then vanishes into thin air. The Doctor and Jo spend a night in the 'haunted' house and meet the attackers - who have time-jumped back from the 22nd century in the hope of changing history. Travelling forward in time, the Doctor and Jo find themselves trapped in a future world where humans are slaves and the Daleks have already invaded. Using their ape-like servants to Ogrons to maintain order, the Daleks are now the masters of Earth. As the Doctor desperately works to discover what has happened to put history off-track, the Daleks plan a time-jump attack on the 20th century. This novel is based on a Doctor Who story which was originally broadcast from 1 to 22 January 1972. Featuring the Third Doctor as played by Jon Pertwee, with his companion Jo Grant and the UNIT organisation commanded by Brigadier Lethbridge-Stewart

Centuries ago, a Zygon spaceship crash landed in Loch Ness. Now, with their home planet destroyed, the alien creatures plan to take over Earth. Their most powerful weapon is a huge armoured dinosaur-like creature of terrifying power that they brought to earth as an embryo - the Loch Ness Monster. The Doctor, Sarah and Harry soon discover that the Zygons have another weapon. They can assume the identity of any human they capture. Who knows which of their friends might really be a Zygon? UNIT faces one of its toughest battles as Broton, Warlord of the Zygons, puts his plan into action and the Loch Ness Monster attacks. This novel is based on a Doctor Who story which was originally broadcast from 30 August to 20 September 1975. Featuring the Fourth Doctor as played by Tom Baker, with his companions Sarah Jane Smith and Harry Sullivan and the UNIT organisation commanded by Brigadier Lethbridge-Stewart