The Keeper, guardian of the Source and benevolent ruler of the Trakenite Union, is dying. Before he can pass over the mantle of leadership to his successor he must avert a growing evil. And to do that he needs the help of the Doctor.
This is a good novelisation of a strong TV story. It is pretty representative of the televised version. There is little extra detail or additions but the story probably wouldn’t benefit from this particularly.
The story has some good elements; not just the return of one of the Doctor’s greatest enemies. The image of Traken society is well conceived and developed. It is different enough from others Doctor Who to stand out. The whole idea of the Melkur and its calcification fits in well with the philosophies of Traken and adds some mystery to the story. The Keeper himself is another interesting concept. The fact that he is capable of materialising inside the Tardis is quite a surprise. There is no clearer explanation within the novel of how the Source works, but that doesn’t really matter to the story. There is also no embellishment on any past relationship between the Doctor and the Keeper unfortunately.
Most of the Trakenites are well realised characters. Tremas becomes a likeable ally for the Doctor which makes his ultimate fate all the more sympathetic. The introduction of Nyssa is handled particularly well and we soon empathise with her. She also quickly establishes a relationship with Adric and the Doctor.
The Doctor and Adric have escaped from E-Space back to N-Space, leaving Romana and K-9 behind at Romana's wish. They are surprised to get a personal appearance from the Keeper of the planet Traken, a planet where only good lives, and where evil is nullified and removed from the environment. The Keeper, fearing his time is nearly at an end, is worried that evil has somehow found its way to Traken, and asks the Doctor to help - he warns that it will be a very dangerous task, but the Doctor and Adric are keen to help. This, to those who fondly remember the era of the Fourth Doctor on tv, is a rather poignant story, as we know that it is almost the end of his Fourth Doctor incarnation. Here he makes new friends (and the character of Nyssa, who becomes a companion is introduced) and enemies; and meets up with someone he'd rather not.
The story ends with the Doctor and Adric leaving Traken, but the story for the reader is not concluded - there's more that we know that the Doctor does not, and this continues on in to the next story, the last of the Fourth Doctor, Logopolis. A good story, written rather in the `typical' Terrance Dicks style, but nonetheless very readable and enjoyable for all that.