"The Curse," by Mark Edwards, in Night of the Flood, edited by E.A. Aymar, and Sarah M. Chen. Down and Out Books, 2018.
This is an example of a Shared Universe book, a concept which I am not going to discuss in detail here because I think I will probably write about it at length in SleuthSayers one of these days.
The short version is this: In the small western Pennsylvania town of Everton, Maggie Wilbourne murdered the men she said raped her. For this she was executed. As revenge, a group of feminist terrorists called the Daughters blow up the dam, flooding Everton. Each story in this book, written by different authors, takes place on the night of this event. Some move the main story line, about the Daughters. Some have no connection to it except for the flood event. This witty story is one of the latter.
Ed and Rhi are Britons, moved to the small town of Everton, PA to dodge what they believe is a curse. It seems that Rhi met a demon named Frank (Frank?) who offered her a winning lottery ticket in return for a horrible deed to be done later. After they have spent most of the money Frank calls up and demands they do the unspeakable thing he wants. When they refuse he threatens them with a curse.
And suddenly their life is burdened with bugs, and boils, and a fire. So they escape to America and encounter, naturally, a flood. In the anarchic night of crime and looters they can probably get away with what Frank demands, but are the willing to do it?
More importantly, is there really a demon named Frank? I'm not the one to tell. But let me remind you of something a very wise man said last week in this very space:
By the way, not all surprises are created equal. If a meteor struck the bad guy, that would be surprising but not satisfying.
The ending of this story is straight out of left field, but I found it completely satisfying.