Roots: Guy N. Smith's foreword lists his own crab-based horror novel Night of the Crabs, plus crab movies Attack of the Crab Monsters, Island Claws, and comic book Mystery Stories issue four. He also mentions Dan Dare of the Eagle, Dixon of Dock Green, and PC 49. There are references to the Beatles, Gulliver's Travels, Faberge, John Donne, Macbeth, the Twilight Zone, Rod Sterling, Frankenstein, Adam and Eve, All Things Bright and Beautiful, Three Little Pigs, Pandora's Box, Gorgons, the Mekon, Nostradamus, Moby Dick (Ahab).
Continuity: The Memory is an experimental organic computer designed to interface with implants grafted into soldiers and provide them with information telepathically. It is designed to absorb the bodies of certain operators; a mechanism was under development to allow it to re-grow bodies for the disembodied minds of these people from their DNA sequences to reward the best performers, but was never completed.
The crabs are cybernetic organisms containing the surgically implanted brains of the primates found on the island. They are capable of adaptation and self-modification. Meathook is four times the size of the other crabs, and contains the brain of Ranger's sister, transplanted against her will.
The primates are grey-haired with tails like lemurs and eyes like bush-babies.
The Doctor goes fishing. He carries a flashlight [surely you mean torch - ed] in his pocket.
Peri goes diving. The Doctor once joked that Peri is always one letter away from peril, a joke that stuck in her memory and which she considers rather cruel. Peri's stepfather Howard (Planet of Fire) sexually abused her when she was a teenager, telling her that it was their secret and that she wasn't to tell her Mom. The Memory absorbs and breaks down her body; the Doctor is able to use the Memory to grow her a new one, restoring her mind to an identical unblemished body. The newly reborn Peri is hairless, but this will grow over time.
Links: The Memory explores Peri's most traumatic memories, including her transformation on Varos (Vengeance on Varos), the Doctor's brief attempt to strangle her following his regeneration (The Twin Dilemma), Sharaz Jek's fawning over her (The Caves of Androzani), and her near drowning on Lanzarote (Planet of Fire).
Location: Island G12 on an unnamed planet, date unknown [the future].
Future History: The war on the unnamed planet was fought between two corporations; they eventually decided that the war was becoming financially unviable and both sides abandoned the planet, leaving the crabs behind.
The Bottom Line: A riveting but emotionally draining read that subjects Peri to horrendous trauma and makes some startling revelations about her past. The characterisation of the crabs is astonishing, helping to make Shell Shock an unforgettable, if disturbing, experience.