Gerry felt her blood turn cold. “Who?” she said. “Who are they?”

“I can’t. They’ll kill me, too.”

“It’s all right, love,” Gerry said, as gently as she could. “Can you tell me who she is, then?”

“Yes. It’s Mimsy.”

“Mimsy?”

“Mimsy Moffat.” The caller paused. “We used to tease her about that,” she said. “‘All mimsy were the borogoves.’” She loved Alice. I remember when we talked about starting a band. We were going to call ourselves Mimsy and the Borogoves.”

Gerry knew “Jabberwocky.” She had been a big Lewis Carroll fan when she was at school, and she still read Through the Looking-Glasss once a year. “That’s a cute name. You can sing and play instruments?”

“No. It was just blethering.”

“You said ‘we.’ ‘We used to tease her.’ Who else?”

“Just me, really.”

“Can you tell me where Mimsy lived?”

“On the estate. Number fourteen Southam Terrace.”

“Where’s that? What estate?”

“Wytherton Heights.”

“Wytherton?”

“Teesside. Near Middlesbrough.”

“OK. My name’s Gerry. What’s yours, love?”

“I’m sorry. I can’t tell you. Nobody must know.” Then she hung up, or switched off her mobile. Gerry immediately hit redial but her call went through to a generic answering service, the kind you get with a pay-as-you-go mobile when you don’t bother to personalize it. She left her name and mobile number just in case, then returned to her computer screen and clicked through to Google Maps.

Wytherton was an area that clung like a boil to the arse of Teesside between Stockton and Middlesbrough, and Wytherton Heights was a sprawling square mile of council estates fringed in the north by a forest of sixties tower blocks and to the south by the main Wytherton Road. Town Street bisected the estate about a quarter of a mile up from Wytherton Road. Southam Terrace, Gerry discovered, lay somewhere near the middle of the largest section.

What little information Gerry could find on the estate told her that it was a mix of postwar council housing. Some people who lived there had bought their houses from the council in the eighties or later, and there were a few older private houses scattered around the edges, mostly turned into student bedsits to service the nearby college. The Google Maps satellite images showed a mix of domestic architecture, from the grime-encrusted back-to-backs and through terraces to sixties brick council houses, maisonettes and old tower blocks. The aerial photographs she managed to dredge up showed higgledy-piggledy streets straggling west of a wasteland of abandoned factory yards with high fences scrolled with barbed wire or walls topped with broken glass. To the west of these houses, by the canal, stood a modern shopping center.