Roots: Alchemy, Reagan's Star Wars project, By Dawn's Early Light, Dr. Strangelove. There are references to Kipling, the New York Times, IBM, Open University, Reagan, Carter, MG, Pythagoras, Colonel Gaddafi, Saddam Hussein, The Prisoner, Range Rovers, Stanislavsky, James Bond, and Shakespeare. The Doctor is reading The Strange Case of Dr. Jekyll and Mr. Hyde.
Goofs: Why does the TARDIS need to restore its power by having the Eye of Harmony absorbing background energy from the outside world? The Eye is a black hole on Gallifrey which powers every TARDIS - the energy drain can't possibly drain all its energy, and if it could, there's no way that level of energy could be absorbed from the surroundings of Earth.
Continuity: Slayers are Yogloth ships. Yogloths are known for their economy of effort.
Khameirians have leathery wings, dark skin, pinched, wrinkled features, and short, curled horns. They are about four feet tall and also have forked tails and webbed hands and feet. The Khameirian will to survive is reputed to be unparalleled. Their homeworlds are in the Antares sector, in the far reaches of the galaxy. They can store their life essence in other forms, and travel through space by placing themselves in suspended animation, with their life force stored in a ship's Essence Chamber, a small egg-shaped stone-like artefact, where it can remain for centuries until it is reconstituted. An Essence Chamber is capable of absorbing Artron energy from the TARDIS. It can use the energy released by a massive nuclear chain reaction to reconstitute the Khameirians.
The Doctor claims to have signed the Official Secrets Act "several times". He carries an unidentified slim, leather-bound book in his pocket. He again uses the alias John Smith.
Sam has grown her hair since leaving Kursaal. She sleeps wearing a long t-shirt.
The Doctor listens to Bach on his record player in the TARDIS. The candles in the control room are everlasting. The Eye of Harmony can absorb energy from the outside world if its artron energy levels become depleted (see The TV Movie and possibly Boom Town). He has heard of the Khameirians but has never met them and knows little about them.
The President of the United States is male, but isn't named [and is probably Bill Clinton unless things have gone differently in the Doctor Who universe].
There are no inhabitable planets in the Rigellis system, which includes Rigellis III.
Links: There is a reference to Kursaal (Kursaal).
Location: America; Abbots Siolfor, near Abbots Clinton, England; Station Nine, 1998.
Unrecorded Adventures: It is several weeks since the Doctor and Sam left Kursaal, during which time they have been to a couple of sunny paradise resorts, on a tour of the monuments of Marsuum, and mountain climbing in the Vasterial Wastes of Julana.
The Doctor claims to have met Mrs Dorothy Frances Gurney and Carl Jung. He was with Pythagoras when he made one of his major breakthroughs in the field of mathematics.
A Yogloth once tried to assassinate the Doctor.
The Bottom Line: Competent, but dull. Richards combines alchemy and a Bond-esque plot about nuclear politics to often thrilling effect, but as is often the case with his novels the villains are utterly forgettable. The Doctor, however, is perfectly captured and Sam is relatively likeable.