From the synopsis that I read of this story, this sounded like a story unlike many other Doctor Who books in the BBC Books line. This sounded like a story that Trevor Baxendale had written and meant it to be a really dark and serious story. If that was the intention, it was achieved with flying colours.
Chronologically, the story takes place in 2009, during the year in which the 10th Doctor travelled with no companion. The Doctor ends up travelling with a small but fiery group of Dalek Bounty Hunters, after a Dalek attack. Whilst travelling with them, the crew ends up with the ultimate prize of a bounty hunter, a inactive Dalek prisoner. Against the Doctor's wishes, the crew slice through the Dalekanium casing in an attempt to try and interrogate the creature inside.
The interrogation takes place about a 1/4 of the way through the book and the writing is of platinum quality. We need to remember that the Daleks have haunted the Doctor all of his life and attempted to destroy his homeworld. Despite all of this, the Doctor is still able to find compassion for the Dalek and tries to stop the crew from torturing it. Even when the Doctor shows mercy for the creature, the Dalek is uninterested and simply tries to aggrevate the Doctor. Every line is one to be impressed by during these scenes.
After the now-dead Dalek reveals a hint about the Dalek Empire's plan, the Doctor and the crew travel to a planet destroyed by the Daleks. There, the Doctor discovers what they are up to. However, the Doctor and the crew also end up as prisoners of the Daleks. Part of the crew are taken as slaves. Some of the writing here reminded me of scenes from the 1979 story "Destiny of the Daleks". In both stories, we see the Daleks deliberately using humans to mine through the rocks, because they relish in seeing humans suffer.
Meanwhile, the Daleks bring in the members of the high council to deal with the Doctor. It is hear we are introduced to Dalek X. Trevor Baxendale's creation can definitely be seen as a deadly one, even the other Daleks tremble at Dalek X. At the end of the story, Dalek X is still able to remain cold and calculating. The ending of the story truly is one to ponder about and fits with the rest of the story.
In conclusion, Prisoner of the Daleks is a masterpiece from BBC Books, it truly is. I would go as far to say that I would have prefered to see this story televised compared to some other new series Dalek stories.