Water was the answer. Well, it had been about nine hours ago, but better late than never. Using both hands to launch herself from her mattress, she stood up and plotted her route across the disarray of her bedroom. She took a wobbly step, and then – gaining in confidence – another, until she made it to the bedroom door. Ellen opened it and peered into the hallway, testing the house for signs of Alexa or Jack. All was still. Her keys were lying on the first step of the staircase. She padded down the hall, the ache of Friday night in her bones, and walked into the open-plan kitchen and dining room, then stopped suddenly when it dawned on her that her socks were being lapped by a tide of water.

Its source was easily locatable: water was cascading from the cupboard under the sink, making the cheap plastic doors flap wildly. She stood there for a minute, mesmerized by the ebb and flow of the shallow lagoon, before her brain clicked into gear.

‘Fuck,’ Ellen breathed. The panic started to rise like the tide of heartburn. It hadn’t been like this when she’d got home. It couldn’t have been. Unless she’d missed it? Or … could she have somehow done this? How could she? She’d only made a vodka tonic. Ellen moved tentatively to the sink, as though the whole thing might blow at any second, her socks now squelching at every step. The tap wasn’t open: the water was definitely coming from underneath the sink. She crouched in front of the flapping cupboard doors, then recoiled when one almost banged her on the nose.

She stood up again.

‘Fuck fuck fuck fuck fuck,’ she moaned. Her voice was higher and more desperate now.

There must be a mains tap somewhere, which would turn off the water at its source, a big switch that would pause the cascade. She crouched closer again in search of one, but all she could discern was the usual tangle of pipes, and a sodden scouring pad at the bottom of the cupboard. She flinched and leaped back as the sink made a low, juddering moan.

A light-bulb moment: the attic. This was where they had unearthed the fuse box, eventually, during a sudden and disorientating blackout. Maybe the switch she needed was there too. Startled by her own quick wit and decisiveness, Ellen turned on her soggy heels, made for the stairs and started running up them, two steps at a time, using the banister to yank herself up.