Doctor Who: The Fourth Doctor

The hugely powerful Key to Time has been split into six segments, all of which have been disguised and hidden throughout time and space. Now the even more powerful White Guardian wants the Doctor to find the pieces. With the first segment successfully retrieved, the Doctor, Romana and K9 trace the second segment of the Key to the planet Calufrax. But when they arrive at exactly the right point in space, they find themselves on exactly the wrong planet - Zanak.

In the great maze of the Powe Complex dwells the dreaded Nimon, a fearsome monster with immense scientific powers. The Nimon has promised to restore the Skonnan Empire to its former glory. But first it demands sacrifice - youths and maidens from the peaceful planet Aneth. The TARDIS collides with the spaceship delivering the victims, and the captured Romana is condemned to be sacrificed to the Nimon. Aided by the faithful K-9, the Doctor goes to the rescue. In the heart of the maze he confronts the Nimon and uncovers a terrifying plot to enslave the galaxy.

Whole civilisations are threatened in these four classic TV novelisations featuring the First, Fourth, Tenth and Eleventh Doctors.