Back on Earth, Anne Travers has learned she is about to be visited by an old friend from America, Doctor Patricia Richards. Lance Corporal Bill Bishop is aware of the visit, and is on hand to meet Richards.
It's a game of cat and mouse, as Anne and Bishop seek to protect the life of an innocent baby – one that holds the secrets to life on the Moon.
to be added
- Colonel Alistair Lethbridge-Stewart
- Anne Travers
- Lance Corporal William Bishop
- Lieutenant Colonel Walter Douglas
- Lance Corporal Sally Wright
- Professor Edward Travers
- Administrator Frank Bland
- Charlie Redfern
- Lance Corporal Tracy Ward
- Tim Gambrell
- Patricia Richards
- Ruby Slant
- The Terrae come from Theia, a former planet in the Solar system.
- Ralph Cornish and the British Rocket Group have just launched Mars Probe 5. Lethbridge-Stewart has only learned there is a British space programme at all as part of HAVOC planning.
- William Bishop's sister, Samantha, has a four-year-old son, Dean.
- This is the first appearance of Dolerite Base, codenamed the Madhouse, base of operations for the Fifth Operational Corps, located beneath Edinburgh Castle.
- At the end of this novel, Anne Travers is officially transferred from the Vault, and becomes the Head of Science & Research at the Home Army Fifth Operational Corps.
- The alien baby is officially adopted by Patricia Richards, and is given the name Brendan. It is said the baby will eventually appear fully human, although he may age quickly for a short period. (TV: K9 and Company)
- Ruby tells Anne that even if Director Vaar, the Dominator, wanted to help, he couldn't as Sebastian Collins is keeping him busy. (PROSE: Mutually Assured Domination)