- Christopher's weakness is silver: he can't perform magic on silver objects, and if he is touching or carrying silver he can't perform magic at all, and is obliged to speak only the truth. This is the result of a spell worked by his father when he was born, an attempt to make silver safe; his father had cast his horoscope, and learned that silver would mean danger or death for him. In fact, his father misinterpreted the horoscope; the danger was not "silver", but "Argent".
- Uncle Ralph (pronounced "Rafe") is the Wraith. He knew that the child of Cosimo Chant and Miranda Argent would have to have some useful magic, and set Miss Bell in the household as a spy to find out what it was. When Miss Bell discovered that Christopher could carry objects between worlds, Ralph laid plans for expanding his operations, which up until then only operated within Series Twelve. The "experiments" he had Christopher doing were firstly to bring illegal materials from other worlds in other series, and secondly to collect data so the gang could develop a way of doing without Christopher.
- Miss Bell, the Last Governess, is of course also a member of the gang. She is the owner of record of the house Tacroy did his astral travelling from (which may also be the same house she and Christopher's mother live in when they return to England, as both are said to be in Kensington).
- Mordecai Roberts, the agent Chrestomanci sent to infiltrate the Wraith's gang, is Tacroy, and has been subverted by the Wraith (although there is more to it than that; see below). In the flesh, his face has insolent and bitter laugh-lines that don't appear on the face of his astral self.
- Miss Rosalie is the young lady who was once the light of Tacroy's life. It was him who taught her to play cricket, before they had a falling-out and Tacroy/Mordecai was posted to London.
- The Dright of Series Eleven likes to study the people of other worlds to see what makes them tick. His usual technique is to leave one of his subjects in another world as a baby to be raised as a local, and direct their life's path; he keeps the person's soul in his possession, which allows him to track them and compel their obedience.
- Tacroy was born in Series Eleven, but was left in World 12A as a baby to be an agent for the Dright's study of good and evil. The Dright made him work first for a good man (Chrestomanci) and then a deep-dyed villain (Ralph Argent). One of the reasons he kept quarrelling with Miss Rosalie is that he didn't dare let her get close to him while he was under the Dright's power.
- The current Living Asheth's magical ability is all her own, not a loan from Asheth. Asheth never shares her power, even with her supposed Living Aspect.
- Mother Proudfoot is actually a nicer person than one might expect, and is quite adept at bending rules when she feels it is justified. In particular, she generally conspires to save the lives of the Living Asheths when their time is up - although Asheth demands a life for each Living Asheth, she's not very discriminating and can generally be fobbed off with a life from one of the Asheth Temple cats. For the current Living Asheth, her favourite of all those she's known, Mother Proudfoot has extended herself a bit futher, and has been saving up to provide for her future. There is, furthermore, a suggestion that she has at least some idea about the Living Asheth's aspirations to Millie-hood. She leaves the Living Asheth in the charge of Chrestomanci, with enough uncut diamonds to fund a full education complete with Swiss finishing school, and returns home with a substitute life (Chrestomanci volunteers one of his, after Throgmorten makes it clear he has no intention of doing so) to report the Living Asheth dead.
- Chrestomanci, having soon realised that Christopher needs people of his own age around him, has already begun steps at the Ministry to have a training scheme for young enchanters set up at Chrestomanci Castle. Jason the boot-boy is the first of the students; his employment as a boot-boy is only an excuse to justify his presence at the Castle until the scheme is properly set up.
- Christopher's father ends up in Japan, where he becomes an influential figure because of his horoscopes. Christopher, suspecting that his parents still love one another really (and also wanting his mother out of the country before she gets tangled in her brother's downfall), arranges for his mother to be informed of his father's location: she goes to join him in Japan, and they apparently live happily ever after.
The lives of Christopher Chant
When Christopher loses a life while astral travelling, it doesn't entirely count, and he loses it again for real when he returns to his own world. This sort of thing can tie serious knots in causality, especially when it happens as often as it does to Christopher. This is how he loses his first six lives (four of them in the astral first):
- Speared by the Arm of Asheth while attempting to remove Throgmorten from the Temple of Asheth in Series Ten
- Speared by a loose curtain rod in his room when Throgmorten attempts to run along it
- Head caved in by a swinging cargo hook (set as a trap for the Wraith's gang) on the dockside in Series Ten
- Head caved in by a swinging cricket bat wielded by Oneir
- Broke his neck falling out of a high, disused part of Chrestomanci Castle trying to get a better look at the old ruined part of the castle
- Broke his neck falling off a high part of The Place Between trying to get into Series Eleven
- Broke his neck falling down the big staircase at Chrestomanci Castle after tripping over Throgmorten
- Roasted by a dragon expressing its displeasure about dragon's blood poachers in Series Eight
- Roasted by a fire-conjuring spell that he over-does because he's frustrated
- Destroys it himself after the Dright gets his hands on it, to prevent it being misused
Two more are removed intact after the fire-conjuring spell but before the showdown with the Dright, and subsequently returned to him:
- Stolen by the Living Asheth, so she can use it as an anchor to astral travel the way Christopher does
- Removed by Gabriel de Witt, stored in a gold ring, and put in a safe place, as a precaution against Christopher losing too many more
Christopher gets the first of these back at the end of the book, and leaves the second in its ring because it is after all a good idea.
Christopher at one point suspects that his tendency to lose lives is a curse from Asheth, since he loses two of them in Series Ten and three more when Throgmorten is present; but the final conclusion appears to be that this was just coincidence.
- Christopher's silver weakness is for some reason aggravated in Series Seven to the extent that merely touching silver makes him physically unwell (although he recovers quickly when he stops touching it).
- Millie, the former Living Asheth, hates the Swiss finishing school, which teaches only impractical ladylike subjects, and runs away.
- When Christopher is in his early twenties, he and Millie get married, and she becomes Millie Chant. He gives her the ring with his life in as her wedding ring, so that it will be safe.