Night Sighs

Because I didn't get up until midday yesterday, I find it difficult to get to sleep last night. I eventually do fall asleep, or at least fall into a light doze. At some point I realize I am awake. There is a sudden sound in the darkness of the flat, making the silence around it even more profound. I ignore it, but then it comes again. It is like a very quick sigh - the sound, perhaps, of a chimney expelling short puffs of steam. The sound comes regularly. I cannot quite work out what it is. I settle on the theory that it must be Andy in his room. Some kind of snoring noise. There are two closed doors between us though, and the sound seems closer than that, too regular for a human sleep-sigh, but there is undeniably something very unnerving about the sound. I think of turning on the light to dispel my nerves, but fall asleep instead, to the piston-like sigh of that undetermined night-noise.