One of the things I look forward to most at Christmas is a good ghost story. I enjoy them all year round, but in the darkness of a northern hemisphere winter, they take on a special resonance. I have my favourites - anything by MR James and several of Charles Dickens' short stories, as well as A Christmas Carol. But there is one story I read every year - it is part of my Christmas, even though by now every word is as familiar as an old and much loved friend. I came across the story in an anthology I bought in a charity shop and it's by a writer who has since sadly died, but whose other work I have searched for and read over the years. The story is Welcome Yule and it was written by Jan Mark. It tells the story of a group of medieval Waits who still sing their carols every year on St Thomas's day, just before Christmas. One year, the new vicar decides to take his parish choir carol singing but he unwisely refuses to listen to warnings that it might be better not to do so on St. Thomas's day, because the Waits might not like it. The vicar goes ahead with his plans and is duly punished for his actions. Towards the end of the story, one of the characters suggests that it might be time to have a word with the vicar and warn him again about crossing the Waits. 'And tell him about Midsummer's Eve,' she finishes. She is told, 'Midsummer Eve's none of his business, or mine. Lord alone knows how long THAT'S been going on.' This, for me, is a tantalising little ending: what DOES happen on Midsummer's Eve? I really want to know! Why did Jan Mark never write THAT story? Every year, as I close the cover with a feeling of contentment, there is the smallest niggle of disappointment to realise yet again that I will never know the answer.