Having been drawn into the Inspector Rebus series through "Rebus: The Early Years", particularly "Knots & Crosses" and "Tooth & Nail", and the underrated "A Good Hanging and other stories", "Rebus: The St Leonard's Years" was an automatic purchase for me.
The three novels, "Strip Jack", "The Black Book" and "Mortal Causes", improve on the previous books with only "Strip Jack" being a slight disappointment The other two are real page turners, as we follow Rebus in pursuit of the "truth" behind each case.
With each book Rankin seems to become ever more comfortable with Rebus as a character, and the complexity of the plot and the number of characters increases. Characters from the earlier books also make welcome reappearances, giving the series real continuity.
The strength of the series for me is the way Rankin dangles the clues in front of Rebus and the reader, making you want to solve the case yourself (I haven't done so since "Knots & Crosses"!) and keep reading. If the next 3 books in the series show the same improvement I can't wait to read them.