A much lauded Russian author, Sergei Lebedev was unknown to me until recently, but if his fifth novel, “Untraceable,” is any guide, he will only grow in stature. Dubbed a political thriller, Untraceable is a riveting examination of state and private morality, anchored in hot-off-the-press news. An ex-Soviet super-chemist in charge of developing ultra toxic bioweapons at an institution called The Island, Professor Kailitin flees the collapsed empire and disappears under a new identity. Now, when another defector is mysteriously killed by a toxin that seems to leave no trace, Kailitin is called to help. But that arouses interest from Putin’s Russia, and two seasoned operatives depart to bring Kailitin down, using his own supreme nerve agent. No blockbuster, Untraceable is artfully structured as a thriller of predators chasing prey, but the author is far more interested in all his characters’ past and present emotional and ethical landscapes. Engrossingly atmospheric, the alternating chapters of Untraceable reminded me of James Sallis’s pithy, noir novels, creating in the reader not only visceral excitement but also lingering disquiet about our inner lives. Superb.