Scotland's ace gun expert/sometime sleuth Keith Calder takes a back seat here to the reluctant bravado of his: new neighbor-writer Simon Parbitter (Adverse Report), and the series' customary gun lore is supplemented with details of electronic gadgetry. Keith has much money and know-how invested in the local high-tech research company of Lord Jedburgh, who is known as Charlie. His product, not yet patented, has to do with a breakthrough change in rifle shot. But the crucial sample, along with a very valuable Purdey rifle, has been stolen by Dave Reece, a ruthless American industrial spy who's decamped to the US, leaving behind a violent encounter with Simon and a murdered company lawyer--Donald Lucas, suspected by Charlie of having sold out. Secrecy dictates keeping the police uninformed and provokes some complicated sleuthing, partly by ham radio. Reece is finally located in Dallas, and Keith persuades Simon to fly there, relying on the help of his old Texas buddy Earl Bell, who enlists three aging good or boys with time on their hands. Together with Simon they miraculously find Reece, abort his plan to sell to the highest bidder, and also reclaim the stolen rifle. There's another killing along the way, with a final victim saved by Simon's canny live-in girlfriend Alice. Simon's diffident manner makes an engaging contrast to Keith's brio. Complications abound in a far-from-seamless plot, but this outing has a rollicking air more Dallas than Edinburgh--it's fast-moving, sometimes broadly funny, and one of Hammond's best.