Roots: Alien. The Doctor quotes Kipling. He hums a tune from Madame Butterfly
Technobabble: Fitz bluffs his way through an explanation of their landing on Eskon: “One of the, um, mercury links blew in the interstitial phase magnetron Artron hoover booster. Rotary arm fell off, I think.”
Dialogue Triumphs: Fitz on his travelling companion: 'Compassion, I've never thought of you as a woman.'
Continuity: Compassion calculates her coordinates from galactic zero centre. The randomiser prevents her from getting a fix on this. The Doctor guesses that the Time Lords are looking for them by using random surface scans, and notes that materialising in a cave will shield them from detection. A rapid series of journeys through the Vortex would result in a build-up of residual Artron energy, allowing the Time Lords to trace Compassion. She has never appreciated pity. She survives a several-hundred feet fall into a crevasse with only minor systems disorientation, forcing her to come to terms with the fact that she is indestructible. Because she absorbed signals from the Doctor's TARDIS when she was in the process of transforming, she has inherited some of the morals that it picked up from the Doctor through the telepathic circuits.
The Doctor carries batteries, which he claims used to belong to Sam or Mel's personal CD player. His pockets also contain a yo-yo, his sonic screwdriver, a dog whistle [K-9's presumably], a cruet set, and a bag of mint humbugs. He notes that he used to carry a set of jump leads for K9. He performs a vanishing cat with a beaker of water. He is well past his one-thousandth birthday. He tells Fitz that Gallifrey had big stones to look under, some with really nasty things living underneath (Fitz jokes about Time-worms, eliciting a sharp look from the Doctor - see the Timewyrm novels). He used to keep jars of tea in his old TARDIS, including Assam, China Yunnan, Lapsang souchong, and Keemun. He mentions Time to Compassion, referencing his previous incarnation's role as Times Champion, which he refers to as Time Lord mythology. Mostly rubbish. He has heard of Spulver worms, but never seen one before. His body heat is considerably lower than that of an Eskoni. He is able to hold back his reaction to being shot with a handbow bolt using a mind-over-matter technique, but cannot do this indefinitely.
Fitz carries a silver hip flask of Grekolian whiskey, which the Doctor has told him not to, and a Zippo lighter. He gets very high on an Eskoni cigar, apparently because of his human metabolism.
Offworlders are rare on Eskon, but not unheard of. Eskon is on the very edge of the Hhork Sector, which is sparsely populated with few level-nine civilisations. Their astronomers' maps include Galaxy 152 and the Tau Graela system, although it is not clear whether the Hhrok Sector is actually in Galaxy 152 [given that Brevus is familiar with the terms human and humanoid, Eskon is probably in the Milky Way]. Eskon has a red sky. It was struck by a solar flare a long time earlier, leaving it scorched and dry (prior to this, it was still largely desert, but had lakes and rivers). Large deposits of ice remained trapped beneath the planet's surface. The area around Baktan has an ambient temperature of 50 degrees Celsius in the shade. The Eskoni mine the ice deposits beneath the planets surface for water, using drills powered by static electricity. The ice mines are a public facility paid for by taxes. Thermium explosives are used to force-melt the ice prior to vaporisation. The Eskoni's oldest cultural artefacts date back thousands of years. The Eskoni are humanoid, but have wide-set brown eyes and tan-fur. They call their young calves. They have discovered electricity, but haven't invented gunpowder. The Eskoni refer to the desert as the Great Dryness.
Baktan was carved out of a vast stone monolith, similar to those in monument valley on Earth, but much larger. The Forum governs it, and the Custodians enforce its laws. The Eskoni use slaves. Regions of Eskon include the Sea of Dryness, the Arid Mountains, and the Drechnar Mountains. Eskon's largest moon is called Kankira and is named after the Eskon God of Sand. There are at least four other moons as well. An anhroha is an Eskon animal. Animals farmed by the Eskoni include gizran reptiles (which are farmed for their meat), balberks and hemmins (both of which are winged creatures, probably birds), and Mogoths. Mogoths are huge furry animals farmed for their milk and meat, and release a pungent smelling saliva when alarmed. They have double-skulls, presumably for protection.
Spulver worms are an amalgam of univalve gastropod and cephalopod. They are flesh-eating parasites, which evolved on the third moon of Aayavex after the indigenous population wiped itself out in a global genetics war. The effects of this war produced a bizarre ecosystem on Aayavex III, which attracted considerable scientific interest. Spulver Worms are incredibly durable, able to survive for decades without eating, to grow at a phenomenal rate, and to survive terrible wounds. They hunt by temperature alone, having no other sensory organs. They have a cluster of tentacles at one end, which they use for hunting. At some point in the past, a cargo ship passing through the Aayavex system picked up either an egg or young Spulver worm from Aayavex III, and then crash-landed on Eskon. The worm survived, although it was badly wounded, and began to grow and reproduce, producing over a million eggs. The pus from the wounded Spulver worm in the ice mine releases Spulver DNA into the water supply, which once digested tries to overwrite the genetic material of the Eskoni, producing the Slimers. At puberty, the Slimers lose their fur, and their skin takes on an unusual texture. Their pores start to secrete slime, hence their name. They all eventually die in an event known as the Squirming, when incubated Spulver worms burst out of their bodies.
Knivors are flying bat-like predators that occupy the caves of Eskon and hunt in packs of approximately a hundred. They live in nests. They are driven off by the sound of the Doctor's dog whistle.
Links: The Doctor asks Compassion if she has ever read Bernice's archaeological textbook Down Among the Dead Men. He also mentions the Daleks. He tells the Eskoni that he has visited dry planets including Aridius (The Chase), Sarn (Planet of Fire) and Dust (Interference), and water-covered planets including Ockora (The Final Sanction), Coralee (Storm Harvest) and Lethe.
Location: The city of Baktan on Eskon, date unknown.
The Bottom Line: An entertaining and fast paced thriller, that benefits from a well-characterised setting and great monsters.