The Shape Shifter by Tony Hillerman (Allison and Busby, £18.99).

With Sergeant Jim Chee and Bernie Manuelito having headed off on their honeymoon at the end of Tony Hillerman's last novel, Skeleton Man, the focus falls firmly on retired Navajo tribal policeman Joe Leaphorn in his latest book, The Shape Shifter.

Leaphorn, fighting the boredom of retirement, decides to dig deeper when he is sent a glossy magazine article featuring a house containing a priceless Navajo rug - for the rug was supposedly destroyed in a fire at a trading post years earlier in a case in which the former cop was involved.

Before long, another former policeman, Mel Bork, has gone missing and Leaphorn has met the rich, urbane animal hunter Jason Delos, who owns the rug featured in the magazine. Leaphorn is unsure if he is on a wild goose chase but when Bork is found dead shortly after visiting Delos, his detective instincts are further aroused.

As always with Hillerman novels The Shape Shifter is set in the dry and baking landscape of America's South West - this one centres on Flagstaff, which lies about 80 miles south of the Grand Canyon.

The book moves at a leisurely pace, reflecting Leaphorn's retired existence, with plenty of time for conversations over cups of coffee and reflections on Navajo culture and legends.

But it explodes into life in a violent denouement which finds Leaphorn in extreme danger - and there is a good twist which adds to the tale's enjoyment.

At the age of 82 and after penning numerous books in the Leaphorn/Chee series, Hillerman is totally at ease with his characters and has developed a relaxed form of storytelling. This book might have benefited from a little more action but it still manages to keep the reader interested until the final page.