“And now, Joanna”-the professor’s voice rose slightly as he shifted on the high stool to make himself more comfortable. “We’ll go back again, if you please, back before the darkness, back before the dreams, back to when you were on this earth before.” He is getting bored too, Sam thought dryly, catching sight of his boss glancing at his watch.

The girl suddenly flung out her arm, catching a pile of books on the table beside the couch and sending them crashing to the floor. Sam jumped, but she seemed not to have noticed. She was pushing herself up onto her elbow, her eyes open, staring in front of her.

Cohen was all attention. Quickly he slid from the stool, and as she stood up he moved it out of her way.

Sam recovered from his surprise and wrote hastily: subject somnambulant; moved from couch. Eyes open; pupils dilated. Face pale and drawn.

“Joanna.” Cohen spoke softly. “Would you not like to sit down again, lassie, and tell us your name and where you are.”

She swung around, but not to face him. Her eyes were fixed on some point in the middle of the room. She opened her mouth as if trying to speak and they saw her run her tongue across her lips. Then she drew herself up with a shudder, clutching at the neck of her sweater.

“William?” she whispered at last. Her voice was husky, barely audible. She took a step forward, her eyes still fixed on the same point. Sam felt the skin on the back of his neck prickle as he found himself looking at it too, half expecting someone or something to appear.

His notebook forgotten, he waited, holding his breath, for her to speak again, but she stayed silent, swaying slightly, her face drained of color as she began to stare around the room. Disconcerted, he saw that huge tears had begun to run slowly down her cheeks.