Jack Reacher, the taciturn ex-MP whose adventures in Lee Child's six previous solidly plotted, expertly paced thrillers have won a devoted fan base, returns in this explosive tale of an undercover operation set up by the FBI to rescue an agent investigating Zachary Beck, a reclusive tycoon believed to be a kingpin in the drug trade. The novel begins with a bang as Reacher rescues Beck's son from a staged kidnapping in order to get close to his father-and trace the connection between Beck and Quinn, a former army intelligence officer who tried to sell blueprints of a secret weapon to Iraq but was murdered before he could pull it off. Or so Reacher thinks, until he spots Quinn in the crowd at a concert in Boston. As usual, Child ratchets up the tension and keeps the reader in suspense until the last page, although his enigmatic hero hardly ever seems to break a sweat. In the tough guy tradition, Reacher and his creator are overdue for a breakout, and this muscular, well-written mystery might be the one.