Before she has a chance to change her mind, Tilda snatches up the laptop, sets it down on the table, opens it and presses the ON button. There is a pause, then a hopeful whirring, and the computer begins to fire up. She backs away, making the tea quietly, as if the slightest sudden sound or movement on her part might shut the laptop down again. By the time she has stirred milk into her drink, the screen is cheerfully displaying her chosen wallpaper; a photograph of the sun setting over the frozen lake.

And now I need Wi-Fi. Which means I have to get the electricity running again.

She goes into the hallway and stands under the fuse box. She has grown accustomed to living in the house without power, and the main switch is still in the off position where she left it weeks ago. She bites her lip, willing herself to stay calm. Stay focused. Holding her breath, she takes hold of the lever and pulls it down. The lights come on. The long-forgotten fridge hums. Next to the telephone socket on the hall table, the Internet router blinks into life. And then there is a sharp snap, and everything goes dark once more.

Dammit!

She stands there in the darkness, quelling the urge to scream.

How can I be so useless? Why can’t I control this thing? The power stayed on at the professor’s house. And I stopped that floodlight falling. This should be easy.

The realization comes to her. She is not wearing the torc. She hurries into the kitchen and fetches it from her bedside table.

‘Right, Thistle,’ she says as she passes the dog on her way back to the hall, ‘hold on to yourself.’ With a determined step, she goes straight to the fuse box, clutching the torc tightly in one hand, and throws the switch a second time. The power is restored. She nods.

Good. That’s good. Okay.

Back at her computer she is uncertain as to how best to hold the piece of jewelry and type at the same time. She is reluctant to put it down, feeling the need for direct contact with it, but at the same time she doesn’t want to put it on again. She can’t imagine trying to search the Internet in the midst of the magic released by the torc. She settles for resting the thing in her lap as she works. Within minutes, she has found a plethora of historical Web sites dealing with early ninth-century Britain.

So much information! Getting through this lot could take forever.