The fluorescent display of the alarm clock on my bedside table said 3:33.

I could feel my heart throbbing in my chest like something with a life of its own, like a rabbit writhing and twisting in a snare that grew tighter the more it struggled. I strained to hear above the booming roar in my temples. My ears probed outside my bedroom door—the landing, the staircase—like invisible guard dogs, constantly sending back information:silence, silence, silence, there’s only silence, we can find nothing. Could I have been mistaken? But I knew I wasn’t. I’d heard the fourth stair scream under a person’s weight.

Sure enough, after what seemed like an eternity of waiting there came the groan of another stair, a higher stair:someone was in the house.

I was paralysed with fear. Since my eyes had opened I hadn’t moved a muscle. It was as if a primitive instinct—to keep absolutely still and not make a sound until the danger had passed—had taken control of me. Even my breathing had become so slow, so shallow that it made no sound, and didn’t move the quilt the tiniest fraction. I thought about the rounders bat I kept under the bed “in case of burglars”, but I was powerless to reach down to grasp it. Something stronger held me frozen and immobile.Keep still, it ordered, don’t make a sound until the danger’s passed.