Decalogue is a series of books based on the television series Doctor Who, published in 1994-1997 by Virgin Publishing. The series consisted of five books, each of which contained ten stories by different authors. In the first three books, the main characters were the first seven incarnations of the Doctor, their companions, and the Master. This is the first of these books.

...And instead of presenting just a collection, we tried to make it even more unusual by uniting the stories with a connecting plot. This means that while it is possible to experience the Decalogue by reading the stories individually, readers who read the book from start to finish will get more out of it.

Ten stories. Seven Doctors. One mystery.