In this 10th installment of his acclaimed Tracy Crosswhite series, Robert Dugoni revisits his beloved protagonist a decade into her career as a detective and 25 years late to the investigation of the mysterious Route 99 serial killer. Uniting cases past and present and finding Tracy at the most difficult moment of her professional life, Dugoni reminds readers that he and his creation aren’t slowing down anytime soon.

Between 1993 and 1995, the Route 99 killer murdered 13 women, raping and strangling them before leaving their bodies in dumpsters off Aurora Avenue North. This multi-lane thoroughfare is crowded with billboards advertising massage and tanning parlors and adult-only establishments. In November 1993, when the killer was just starting out, Vic Fazzio was only three months into his stint as a homicide detective in Seattle’s Violent Crimes Unit and was called to the scene where the fourth victim was discovered. Nine victims and over two decades later, the police force is no closer to finding an answer.

"As a longtime reader (and lover) of this series, I am always surprised to see where Dugoni takes his protagonist and the new investigations she embarks on. ONE LAST KILL is no exception, and I already am eager for book 11."

In the present day, Tracy is at a crossroads in her career. After discovering a corrupt Seattle drug task force in her last case and finding herself unable to bring justice to the many deceased or protected players --- including Chief of Police Marcella Weber --- she feels burned out. Her new role as the sole member of the Cold Case Unit is not helping, and she is sorely missing the camaraderie of her partners for the last 10 years: Faz, Del and Kins. When she is abruptly called to Weber’s office, she expects yet another power play or dead-end demand. Instead, she learns that the Seattle Times --- which decades earlier lambasted the police for their failure to find the Route 99 killer --- is planning a 25-year anniversary piece about the cases.

Weber tasks Tracy with reopening these cases and insists that she work with her nemesis, Captain Johnny Nolasco, the lead detective on the original case. Nolasco is a man whose ineptitude is matched only by his misogyny, both of which are outweighed by his contempt for Tracy. Politics, as always, comes into the fray with the Seattle Times’s tight timeline for their report, and Weber makes no secret that she happily will let Tracy take the fall if the killer is not unmasked this time. With both Weber and Nolasco breathing down her neck, and her own disillusionment propelling her forward, Tracy is on the case.

Every good cold case begins with a reinspection and reinterpretation of the original case files, and what Tracy finds in the Route 99 records is instantly compelling. Between his 10th and 13th victims, the killer began targeting middle-class women instead of sex workers. His MO did not change otherwise, and though this detail was never released to the public, he continued to carve angel wings into the shoulder of every victim. So why the sudden change in targets, and why the abrupt end to the killings in 1995?

As Tracy’s questions grow, Nolasco gets more and more sensitive, though not for the reason readers might expect. He isn’t quite the blowhard he was in previous novels. When it comes to the Route 99 killer, he cared about the victims and finding them justice, and this personal touch brings out a new side of him that has never been seen before. With red herrings abounding and the threat of new public interest (and therefore copycat killers or even a reemergence of the original killer) looming over them, Tracy and Nolasco draw upon one another’s strengths as detectives and partners to tie the past and present together and wipe away a dark mark on the police force’s record.

At the same time, updates to investigation techniques, DNA analysis and forensics turn this book into a fascinating history, with flashbacks to the initial investigation illuminating just how far police work has come…and how far it may still go.

While every book in this series can be read as a stand-alone, this one draws heavily on its predecessor, WHAT SHE FOUND, which exposed serious corruption in the Seattle police force. Finally at a good spot in her personal life, Tracy is deeply troubled and alarmed by these events. ONE LAST KILL picks up almost immediately where the previous book left off, making this feel like a satisfying, complete “two-parter.”

But Dugoni is still quick to welcome in new readers, effortlessly dealing out entire histories without weighing down the plot. He also uses his skillful character development to make obvious the intentions and motivations of his key players, while still layering them in complexities and nuances. Seeing a new side of Nolasco was particularly satisfying. While I’ll never quite forgive his treatment of Tracy over the last nine books, it’s exciting to root for a new character, and I believe that Dugoni has blown open his options for future alliances and friendships.

As a longtime reader (and lover) of this series, I am always surprised to see where Dugoni takes his protagonist and the new investigations she embarks on. ONE LAST KILL is no exception, and I already am eager for book 11.