This is an interesting surmise. The 6 authors all write historic detective fiction, but they come together to write a short story featuring their own detective, but the short stories are all related. In this case they all feature a book of prophesy written be a deranged/inspired (delete as appropriate) Irish monk in the 6th Century. The book contains quatrains that predict the future oft he world and this poor book gets invooved in all sorts of events as different groups want it in order to use it their own ends. A good idea, well executed. I've read several of the authors writing their full length books and I can see I might investigate those I've not read in full.
 - The Medieval Murderers)