The Overstory, by Richard Powers THE OVERSTORY RICHARD POWERS W. W. NORTON & COMPANY. INC., 2018 $27.95 512 PAGES Richard Powers, a National Book Award winner, has been writing science- and tech-related fiction for more than 30 years. In his latest novel, The Overstory, he displays his mastery of the craft with an innovative interplay of theme, structure and style. The first 150 pages trace nine characters – nine “roots” according to the section heading – each equally compelling. The…