She is panicking now, unsure of how to proceed. She starts to call Greg but then remembers the door in the inner hall that links the flat to the house upstairs. She has to press her hip against it to slide the bolt, but when she does, the door opens easily.

The staircase is dark, a dank smell invading her nostrils. She moves blindly up the steps until she reaches the door at the top, and it is only now, as she pushes it open, that she feels hesitation. The silence of the house announces itself. The vastness of the space looms in the cavernous hall. Doors open on to rooms dark with unfamiliar furniture. She tries to recall the layout of the space from the one occasion she has been here, at the same time waiting for her eyes to adapt to the gloom.

The steady drip and patter of water calls to her, and she knows that it’s coming from upstairs. She puts an unsteady hand to the banister, and begins her ascent.

‘Hello?’ she calls. ‘Anton?’ But her voice is less forceful now that she is in his space, cowed by the unfamiliarity, the persistent sense that she is trespassing in the home of a possible killer. Fear fills her chest as she moves blindly up the stairs, alert for sudden movements from the shadows.

As she reaches the top step, the carpet squelches. The floor is saturated, and it stirs an urgency within her, pushing her forward. She follows the noise and gathers her nerves at the door before pushing it open on to the bathroom.

The noise of the water reaches its crescendo here, both taps open as water spills over the lip of the bath, splashing off the tiled floor before running off into corners. Immediately she sees a leg draped over the side of the enamel, skin grey in the dim light, an arm dangling, his head partially submerged. An involuntary cry escapes her lips as she rushes forward, turns off the taps and plunges her hand deep into the water to release the plug. She grapples with the body, trying to haul Anton up beneath his armpits but his skin is slippery and his weight made heavy with water and lifelessness. He slithers from her grasp and she has to plunge her arms in again, trying to gain some kind of purchase.

The water is tepid, and his skin is so cold against hers that she thinks he must surely be dead, yet still she struggles and eventually marshals enough strength to haul him out. The thud of his body on the tiled floor fills her with a new dread.

‘Anton!’ she screams, looking for signs of life in his face, but there’s nothing. She has dropped her phone on the floor in her fright, and when she reaches for it now, she offers up a silent prayer that it will still work.