Cambridge 1940. Winter. DI Eden Brooke's eyes are over-sensitive to light, so he tries to work at night. He was tortured by Turks in the last war. His father was a Nobel winner. His son Luke is in Belgium. His wife shift-works in the hospital. His daughter is 3 months pregnant, her husband Ben a submariner.
A prince is due to visit the city. A boy in a sack has been thrown in the river - a newly arrived evacuee from London, an Irish Catholic. He (Sean Flynn) was going to attend the church school. He'd been a petty thief according to the boy he'd befriended on the train. The priest seems over-friendly with the housekeeper. The head teacher's young wife Kathleen is pregnant.
A factory is vandalised by the IRA. It produces TVs and radios - why was it a target? He learns that the factory's involved with radar and that a special set was missing. The manager belongs to The Galton Society - eugenics.
He has sleeping problems. He thought they were because of his desert experiences but then realises that his father had similar problems. He takes advice from a friend who uses guinea pigs and cockroaches to explore circadian rhythms. Doric, a night porter at his old college, is one of his night friends.
The local Irish suspect known as Patrick is found dead. He's actually Colm Hendrie, a church regular, a gentle giant. He had a photo of the missing boy's mother. They get a telegram saying Ben (son-in-law) missing. The school caretaker Joe Smith missing. He looked a bit like Hendrie's possible killer and a factory intruder. He used to borrow Hendrie's van - a distinctive 3-wheeler.
They find out that the boy's mother in London is actually Mrs Walsh. His biological father is the head teacher of the church school in Cambridge. They split because she fell in love with a widower. She thinks his first wife died. He's found hanging in the church, not quite dead. Did he murder the boy to stop his bigamy being revealed?
A train junction is bombed. Bomb-making equipment is found in the head-teacher's cellar. He was being blackmailed by Smith. When interviewed he said Smith and Hendriem had taken a photo of his first wife from him. The bomb at the factory wasn't anything to do with their terrorist cell. Brooke realises that the witness to the factory break-in was Dr Bodart, a member of the Galton Society who could have stolen the manager's keys and taken the radar equipment. She's disappeared from Cambridge in her houseboat.
When Mrs Flynn arrives from London to identify the body, she says it's not Sean, her son. Brooke sees Smith laying a fusewire for a bomb under the Mathematical bridge (where the prince would go). He shoots him. The housemaid is Smith's mother.
Ben's alive, captured. Bodart killed herself in a bunker, with the radar set. Her husband was being held by the Nazis. Sean and a naughty boy called John had exchanged identities on the train to Cambridge, for a laugh. So the real Sean is alive after all.
Period details are packed in. Some of the sentences caught my eye -
- "Brooke saw that each hamster was marked with a small label attached to a foot, like a consignment of evacuees from the East End"
- "Her eyes flitted over Brooke's face, as if collecting data from a particularly fascinating pot plant" ... "Not for the first time he felt that his damaged eyes had saved him from such a life, observing minutiae, recording results, building a career out of patience"
