A near-future dystopian London is the setting for the story (I’m working on the basis that you aren’t a neo-fascist racist xenophobe brownshirt and therefore it is dystopian rather than utopian). Whilst Shooter’s Hill has been returned to the dense woodland of its past, in it lurks a dark secret.
The protagonist (who evidently appeared in an issue in Interzone’s sister magazine Black Static a couple of issues back) comes across a clock, and the story behind it suggests that the time piece could be a means of turning back the clock on his recent widowhood. A conversation with the clockmaker explains more about what is happening in the woods, and whilst time can not be turned back like the hands on a clock, it is more malleable than might appear, as he finds out.
The narrator’s perspective is handled well, and Allan has the good sense not to make it a happy-ever-after story, in a story that has an intriguing setting and leaves the reader wondering about what happens next.