In Florentin’s (In the Talons of the Condor, 2013) thriller, a teenage girl’s search for her missing sister takes her into the seedy world of pornography and pedophiles.

Eighteen-year-old New Yorker Rachel Wallen’s younger adopted sister, Olivia, has been missing for four days. By visiting the runaway shelter where Olivia volunteered and perusing Olivia’s Yahoo Messenger, Rachel learns two startling bits of news: Her sibling was working as a stripper and chatting with Achara, a sex slave in Thailand who happens to be Olivia’s biological twin, about whom Rachel knew nothing. Rachel follows Olivia’s trail right into the homes of sleazy men who prefer underage girls (Rachel tells them she’s 14), hoping that one of them will know where Olivia is. Simultaneously, Rachel is looking for a way to bring Achara safely to the U.S. But she’ll soon discover that the worst of the men is the Webmaster, who tortures and murders young girls on a live feed for the highest bidder. Florentin’s passionate novel overflows with tension as Rachel encounters numerous suspicious, shady characters with new friend Sonia, whom she meets at the Pleasure Palace, a peep show where Olivia had been working under a pseudonym. Someone hires a hit man, too, and the Webmaster’s identity remains a secret until near the end. Rachel initiates her own investigation, which involves stealthily hacking into the men’s computers to find info (e.g., photos) related to Olivia, but she’s smart enough to cooperate with the steadfast Detective John McKenna, one of the book’s few admirable male characters. The author does seem to be criticizing the pornography industry in general, not just pedophiliac smut; love dolls at the Pleasure Palace are described as simultaneously disturbing and frivolous: Their open mouths are initially “a silent scream” but later “an extruded yawn.” Despite the story’s contentious subject matter, Florentin handles it with finesse and as much delicacy as possible; even torture sequences, including both male and female characters, are opportunities to elevate the suspense, not to generate discomfort by lingering on unsettling images. The final act is relentless, as Achara, armed with her (faux) passport, tries to flee Thailand and her captor, Tong. The Webmaster, meanwhile, has accumulated more than one potential victim for his latest smutty webcast.

A fierce thriller that doesn’t offer many chances to catch a breath.