What is a predatory mountain lion doing in suburban Minnesota? This is the question that wildlife investigator Sam Rivers must solve as he tries to unravel a rare, fatal attack on a corporate exec out for a morning bike ride. The man's mangled corpse is discovered shortly before he closes the deal on a secretive sale of his company, one even his workers don't know about.

The local sheriff and his deputies nail down enough evidence to consider it an airtight case of a deadly cougar on the prowl along the untamed Minnesota River Valley on the outskirts of Minneapolis.

If the plot line sounds familiar to some faithful Star Tribune readers, it should. "Cougar Claw" is an enhanced, fleshed out version drawn from a serialized fiction tale, "Savage Minnesota," that ran for weeks in the Star Tribune in the hot and humid days of 2014. The exciting summer read still pulses at the book's core, but it comes in an entirely fresh version for those new to the project.

Rivers is a forensic biologist with the U.S. Fish and Wildlife Service. He's taken on several investigations of a natural predator attacking a human, and right away the evidence of this one starts looking suspicious. With resistance from local law enforcement, and with a reporter hot on his trail to get the truth, Sam pieces together fact out of fiction to re-create the deadly scene and find out who stands to benefit most from the executive's death. Because, as any detective knows, it almost always traces back to the money.

In "Cougar Claw," Rivers is paired with a wolf-dog partner, Gray, which he adopted in a previous story (the North Woods-based "Wolf Kill"). His affection for Gray, and Gray's honed tracking instincts, make the wolf hybrid an indispensable member of the team.

Griffith is a fluent student of the Minnesota outdoors. His detailed storytelling makes the rugged landscape come alive, becoming a major character in his writings.

And Griffith's popular creation, Sam Rivers, is a striking star, handsome, playful and deeply knowledgeable in his field. Turns out he's not so bad at unraveling the darker side of human nature, too.

Ginny Greene is a Star Tribune copy editor.

Cougar Claw

By: Cary J. Griffith.

Publisher: Adventure Publications, 383 pages, $16.95.