Would my psychological gothic thriller novel The Birds Began to Sing qualify? It's about an aspiring novelist who enters a competition to write the final act of an unfinished, unpublished manuscript by a famous deceased author (the winning version is published). She does this alongside other competitors at the family home of the deceased author - a gothic mansion on the edge of Dartmoor. Here she is subjected to several mysterious competition rules, and has to write the ending whilst staying in the house for a fortnight. Weird things start to happen...