To make a success of studying Mark's gospel, you have to be a detective. That is the judgement of Eric Johns and David Major, who begin by setting out the clues, and then go on to examine the evidence. The result is a pleasing commentary on the earliest of the four gospels, written in a language ideally suited to the non-specialist and in a style designed to help the beginner. It is particularly suited to those preparing for GCSE. But the simplicity...