Girl from Kandahar

In Afghanistan, British secret servicewoman Marcie Brown, posing as the third wife of one of ISAF's most trusted operatives, is killed in a drone strike.
Or at least, that's what the official report states. Deep inside enemy territory, what remains of her body is deemed irrecoverable.
Seven thousand miles away, her grieving husband, MI7 officer Nicholas Fleming, joins a police investigation which stumbles onto an Islamist plot to bomb central London. Handed responsibility for the counter-terrorism initiative, he uncovers evidence that one of the bombers is his wife.
By degrees, the utterly unbelievable becomes plausible and, at last, undeniable.
And to make matters worse, there's evidence that she's slowly recovering her memory ...