While looking for something completely unrelated, I found that Michelle narrated a story for BBC Radio in 2007 called "The Cycle". Written by John Connolly and broadcast as part of the series "The Lunar Effect", a collection of five stories around the full moon, "The Cycle" was first broadcast on BBC Radio 7 on 22 October 2007 and subsequently repeated on Radio 4 Extra.
Description from the BBC:
On her way home from work on an almost deserted train, a young woman starts to suffer pains that we are led to believe indicate her period is imminent. When two troublemaking youths board the train and there is a subsequent delay, the boys' unwanted attention, the woman's increasing pain and the effect of the full moon result in the demise of her tormentors by unexpected means...
Here is the full recording: