THERE is a feeling, as you first delve into Brighton Belle, that you are arriving late to a party.

The early pages read more like a second book in a trilogy than an opening gambit.

Set amid the grey, postwar austerity of 1951, Sheridan's tale slowly drip-feeds us details of heroine Mirabelle Bevan's former life as a secret service agent: her cloak-and-dagger, behind-the-scenes work helping to track down Nazi war criminals, her subsequent role in the Nuremberg Trials and her broken heart after the death of her dashing married lover.

Mirabelle's a bit of a cold fish and not very likeable initially. Sheridan takes a calculated risk with this tactic, but ultimately succeeds in drawing you in.

Beneath that prim exterior lies a fearless, fly-by-the-seat-of-her-pants kind of gal. One part Nancy Drew, two parts Jessica Fletcher, Mirabelle has a dogged tenacity to rival Poirot. Then there's her sidekick Vesta, a bright young insurance clerk who shows great promise when taken under her wing.

Working in a debt collection agency, when her boss disappears, Mirabelle charges herself with tracking him down. Throw in a missing pregnant Hungarian refugee, a kidnapped priest, a sociopathic madame, some Nazi gold bullion and a betting scam, and we have ourselves a proper old-fashioned murder mystery.

Sheridan does have an eye for detail, not least in the unflinching account of the casual racism of the era. We witness Vesta, who's of Jamaican origins, enduring stares and hushed whispers in a chip shop queue, and being arrested by a police officer simply on account of being "a darkie" on the wrong side of town.

Mirabelle, meanwhile, is the perfect foil to the sexism of the time. One of her best lines comes during an exchange with Vesta on the mechanics of spying. "Well, I've read the manuals," says Mirabelle. "Actually, I wrote one or two ..." Which sets things up brilliantly for the there's-no-pilot-so-I'll-goddam-land-this-plane-myself-type capers which follow.

While Brighton Belle doesn't quite pitch to the weight of the likes of Alexander McCall Smith's The No 1 Ladies Detective Agency, it's definitely a grower. Buy it now to stick in the beach bag.

Murder mystery