Well, first, my hardcover copy is a first edition, one that consistently misspells "hobbyist" as "hobbiest". (Which consistently made me think "Of all the hobbies in the world, bomb-making is the hobbiest.") Amazon's "Search inside the book" feature says it's been fixed in current editions. Wonder if my copy is worth anything?
Robert Crais's usual heroes, Elvis Cole and Joe Pike do not appear in this book. (But the semi-pervy LAPD criminalist John Chen shows up, so we know it's set in the same universe.) The hero here is LAPD detective Carol Starkey, and she's kind of a mess. Understandably, after having been temporarily killed back when she was on the bomb squad. She sustained a considerable amount of physical and psychological damage, and these days she subsists on cigarettes, Bombay Sapphire, and Tagamet. She has no life other than her job.
She's no longer on the bomb beat, but she's called in when Charlie Riggio, who is, gets killed by a devilishly-constructed pipe bomb left by a mini-mall dumpster. Investigation reveals that Riggio made no blunders; instead, the bomb was set off via remote control. So it was specifically aimed at killing a bomb squad cop.
Worse, the bomb was designed similarly to those left by a notorious bomber-for-hire, "Mr. Red". This brings the Feds into Starkey's investigation, specifically Jack Pell of the ATF. This causes understandable friction, especially when Pell starts acting more than a little unconventionally.
It's a real page turner, and it's buttressed by the impressive amount of research Crais must have done to get the details right: not only police procedure, but bomb squad procedure, bomb design, and the squirrelly nature of criminals that like to make things blow up. (For some reason they seem to be missing fingers.)