She still had the lamp in her hand. In pushing it away the first time, the man had apparently dismissed it – and her – as a threat. But she wasn’t as weak as he seemed to think. She swung the lamp up fast and hard, striking him on the side of the head with the metal base.

He cried out. His eyes flared in pain and anger. His grip loosened just enough for her to squirm free. She made a dash for the door, but he grabbed her by one ankle, pulling her off her feet as she ran.

She fell. One of the upturned desk’s legs was directly in front of her. As she plunged towards it, she knew her head was going to hit it.

The blow was sharp and stunning. She went down into a pool of darkness.

Oblivion didn’t last long. Wada regained a woozy form of consciousness to find herself lying across the underside of the upturned desk, with her back against one of the legs, her shoulder bag pinned beneath her. The man was in front of her, but looking away, rummaging through the sarin box, searching for … whatever he was searching for.

At that moment there was a banging on the front door. She heard a male voice shouting on the other side of it. Wally Stapleton was her guess. ‘Open this door. I know you’re in there. You took the key. Open up right now.’

The man stopped rummaging and glanced towards the door. Perhaps he was regretting hurling the desk out of his way so noisily now. It had alerted the Stapletons to Wada’s presence in the flat – and inadvertently to his.

‘I’ll call the police if you don’t open up. I’ve got my phone in my hand and I’m going to dial 999 if you don’t open the door right now.’

The man grunted in irritation. This was evidently a complication he hadn’t anticipated. He pulled a black plastic bag out of the pocket of his jeans and flapped it open. He emptied the box into the bag, then grasped the computer that was lying screen down on the floor and stuffed that into the bag as well. Wada lay quite still, hoping he’d assume she was still unconscious. The banging on the door continued.

‘All right. That’s it. I’m hitting the buttons now. Nine, nine, nine.’

The bag split as soon as the man picked it up. Some of the documents, including the wallet of photographs, spilt out on to the floor. He gave another grunt of irritation. Cradling the split bag under one arm, he stooped and retrieved the photographs, but ignored the rest and hurried out of the room without even glancing at Wada. She saw him take a turn into the kitchen and guessed he must have broken in via the fire escape.