Wiser Than Serpents — Susan May Warren

Her sister had vanished, trapped in a human slavery ring. To find her, FSB agent Yanna Andrevka arranged her own kidnapping into Taiwan's sex-trafficking trade. And found herself with no way out.

Until Yanna discovered an ally deep undercover: Delta Force captain David Curtiss. He was after the kingpin of the Twin Serpents, the organized crime syndicate that had Yanna--and hundreds of others-- in their clutches.

With opposite agendas, David and Yanna had to rely on each other to outwit their cold-blooded enemy.