Green for Danger, by Christianna Brand

"'If this were a detective story, he'd be the murderer for a certainty, though,' said Barnes. 'They always pick on the benevolent elderly gent, because you'll never think it could be him!'

'Ah, but nowadays they're more subtle; they know that the reader's wise to that trick and the older and more benevolent a character is, the more he'll be suspected.'

'Perhaps it's gone all the way round and come back full cycle,' suggested Barnes, laughing; 'and elderly gents and paralytics in bath chairs are suspects number one all over again because the reader doesn't think the author would be so obvious. Anyway, this isn't a detective story, and it certainly wasn't old Moon.'

'So that leaves you and me and the three girls,' said Eden, grinning sardonically. 'A charming alternative.'" (p. 216)

My good friend Father Christmas added this to my Mum's stocking based on the blurb, thinking it a suitable present for a former nurse who likes a murder mystery. My Mum's first reaction was, "Oh, I knew her." In 1971-72, my late Dad was a joint junior registrar at Mount Vernon and Middlesex hospitals, working under Brand's husband, the surgeon Roland Lewis.

First published in 1944, Green for Danger involves victims of air raids in 1943 being brought into a military hospital in Kent, where someone bumps off a number of patients and staff. A film version was released in 1946, directed by Sidney Gilliat and starring Alistair Sim as Inspector Cockrill, with action moved forward a year to 1944 and the V-1 offensive, presumably for greater cinematic impact.

The book begins with postman Joseph Higgins pushing his old, red bicycle towards the new Heron's Park hospital to deliver seven letters. They're all from new members of staff and we get a quick glimpse of each character before being told that one of them will, a year later, murder this poor postman.

In Chapter II, we jump forward a year and are quickly caught up in the bustling, bantering hospital on the night of an air raid. The local ARP centre and a pub have been hit, so lots of patients are coming in, wounded and grimy and scared. At the same time, we get more details of stuff going on under the surface - the staff's love affairs and unrequited passions, their terror of the air raids, the people they've already lost. 

Higgins is brought in with a fractured femur, the sole survivor of the ARP Centre. The doctors decide to operate. Higgins and his wife are both nervous but are assured it's a routine procedure. In he goes to theatre, our seven suspects all on duty. By the end of Chapter III he is dead.

At first it seems that no one is to blame - sometimes these things just happen in theatre. Inspector Cockrill is called in as a matter of routine. But he starts to suspect that something more sinister has gone on and then someone else is murdered...

It all moves along breathlessly and the different characters are well drawn, with some suspenseful moments such as when another man goes into theatre with the same suspects on duty, plus the Inspector watching them. The air raids and murder make for a tense setting anyway, and there's something a bit naughty in the staff's complex romantic intrigues, their efforts to solve the mystery for themselves and the games they play with the police officers assigned to watch them. 

Cockrill deduces who the killer is fairly early on but requires more evidence before he can confront them, which is effectively a challenge to the reader to work out what he has spotted from the clues given so far. On more than one occasion, things don't go as he expects - putting lives in danger.

Brand keeps us guessing skilfully. There are some fantastic twists at we rattle towards the conclusion - one section ends with a character springing forward to attack and we think they are the killer exposed. In the next, brief section, the Inspector intercedes to stop this person and then arrests someone else. "Oh, it's them!" we respond to the sudden attack. And then, almost immediately, "Oh, no, it's them!"

In the closing chapter, the survivors compare notes and look towards the future. There are still further twists in the tale. One character seems to be proposing to another - and then it's clear that they aren't. The other character, hopes dashed, 

"stuck our her chin, made a little joke, and nobody knew there was anything wrong at all." (p. 255)

We leave them, laughing and talking, for all we are haunted by the trouble we know lies just under the surface.