Mystery Writers of America Grand Master Block has been writing for more than 50 years and walking slightly longer, according to this memoir notable for frequent flashes of the author's keen wit. In the introduction, he accurately and honestly advises the reader that the book is as ""every bit as self-indulgent as it wanted to be."" Block goes on to provide lengthy details of his various forms of ambulation, from long solo walks as a seventh grader to a walk across Spain to Santiago de Campostela. Mostly he recounts his experiences as a runner and a racewalker in races ranging from 5Ks to marathons and 24-hour races. Runners or walkers will enjoy Block's accounts of his trials and triumphs, including a strange hiatus of more than 22 years. (Block was in his 40s when he stopped racing and in his 60s when he resumed walking marathons.) Mystery fans, unless they're Block completists or running enthusiasts themselves, may want to take a pass.