‘Are you fond of babies, Mrs Rains?’ Wexford asked, and got an almost frightening response.

Hard lines bit into Mrs Rains’s face and her redhead’s pale eyes flashed. ‘I’d be an unnatural woman if I wasn’t, wouldn’t I?’ What else she might have said – a defence? An explanation? – was cut off by the arrival of a woman in her late forties whom she introduced in a mutter as her mother. It was left to Wexford to find out that this was Mrs Leighton who had left Pippa in a drugged sleep and Trevor trying to answer Sergeant Martin’s second spate of questions.

Mrs Leighton was sprightly and not too concerned. ‘Well, babies that get taken out of prams, they always turn up safe and sound, don’t they?’ Her hair was dyed to a more glorious red than her daughter’s natural shade. She was on her way to babysit for her son and daughter-in-law who had a six-month-old son, and she had just looked in on Pippa to collect the one pound twenty she owed her for dry-cleaning. Imagine what she’d felt, the whole place full of policemen and Karen gone. She really thought Trevor or Susan might have phoned her, and now she was in two minds whether to go and babysit for Mark or not. ‘But she’s bound to turn up OK, isn’t she?’ she said to Wexford.

Wexford said they must hope so, and then he and Burden left the two women to argue between themselves as to which was the more important, keeping a promise to the son or commiserating with the daughter.

The world, or this small corner of it, suddenly seemed full of babies. From behind two doors on the ground floor came the whimpers and low peevish grizzlings of infants put unwillingly in their cots for the night. As they left by the glass double doors, they passed on the step an athletic-looking girl in sweater and denims with a very small baby clamped to her chest in a canvas baby carrier. The car park was filling as men returned home from work, some of them commuters from London, and among them, walking from a jaunty red sports car, a couple swinging between them a baby in a shallow rush basket. Wexford wondered just how many children under the age of two lived in those flats and small neat houses. Nearly as many as there were adults, he thought, and he stood aside to let pass a girl pushing twins in a wide push-chair.

There was very little more that he could do that night beyond embroiling himself in another discussion with Burden as to the reason why. Burden put forward several strange suggestions. Having previously declared that he couldn’t think of a single motive, he now posited that the baby-snatcher was due to have her own baby immunized against whooping cough on the following day. She had read in the newspaper that this could cause brain damage but was too diffident to refuse the immunization, so planned to substitute someone else’s baby for her own.