There’s something infinitely tantalising about Robert Dawson Scott’s new play The Electrifying Mr Johnston, now on tour across Scotland in a small production by Mull Theatre, part of Comar arts. The subject is a magnificent one: the too-easily-forgotten life and works of Scotland’s great wartime secretary of state Tom Johnston and his evolution from young Independent Labour Party firebrand to a towering establishment figure who served in Churchill’s war cabinet and, in the late 1940s, wheeled and dealt his way relentlessly through his mighty and still debatable project to bring hydro-electric power to the Highlands.