CAPITAL CRIMES --- a worthy successor to 2004's DOUBLE HOMICIDE --- is the second in what hopefully will be an ongoing series of collaborations between Jonathan and Faye Kellerman. The premise of this experiment is an interesting one: each volume contains two novellas involving characters previously unknown within the Kellermans' respective worlds, set in cities other than Los Angeles. The husband-and-wife writing team ostensibly collaborates on each work, though "My Sister's Keeper," which takes place in Berkeley, California, seems more Faye than Jonathan, with the opposite being true in the Nashville-based "Music City Breakdown." Both stories, however, have much to recommend, regardless of which author you may favor more.

"My Sister's Keeper" introduces the odd partnership of Will Barnes and Amanda Isis, Berkeley Police Homicide detectives who are investigating the brutal murder of California state representative Davida Grayson. The case does not lack for suspects, given Grayson's fringe politics and sexual ambiguity. Despite Barnes's lone-wolf cowboy personality and Isis's team approach to nearly everything, they somehow mesh without quite meeting as they follow their respective instincts.

The silent third protagonist of the novella --- Berkeley --- is an interactive backdrop to the story, and even those of us who don't quite get the ambience of the city that forever will live in San Francisco's shadow will be charmed by the presentation herein. This is a genuine whodunit, one that keeps the reader guessing until the very end, and the tenaciousness of Barnes and Isis is inspiring, even as the victim becomes a less sympathetic character as the story proceeds.

The murder victim in "Music City Breakdown" is Jack Jeffries, a one-time southern California music superstar whose best work and years are long behind him. Venturing to Nashville to play a benefit concert, he is found murdered in an all-but-deserted section of the city. The Nashville Homicide team of Baker Southerby and Lamar Van Gundy is assigned to investigate. Southerby and Gundy are a Mutt-and-Jeff pairing who play off each other quite well, even as they navigate their way through a morass of Davidson County politics and the baggage of the victim's past.

"Music City Breakdown" has a strong real-world feel to it; elements of Jeffries's career and personality are instantly recognizable in a hippie-era musician who recently completed a summer with his equally well-known bandmates, and some of Nashville's more colorful, if not well-known, characters weave in and out of the story. The identity of the murderer, and the motive, will come as a surprise, but the most intriguing part of the novella is Southerby's biographical coda to the story, which answers some questions about the man but makes the reader yearn for future encounters.

The short novels in CAPITAL CRIMES are not entirely divorced from the Kellermans' respective mythos --- Peter Decker makes an appearance in "My Sister's Keeper," while Alex Delaware plays a quietly prominent role in "Music City Breakdown" --- but the change of scenery and characters in each demonstrates, once again, the breadth and depth of the Kellermans' craft and imagination. These are crime scenes I would not mind returning to again and again.