The Christophers holds back from showing us Ian McKellen ’s Julian Sklar in his full glory. Still, we know it’s the actor the moment Lori Butler ( Michaela Coel ) walks through his door. We can hear that thunderous, melodious voice of his bouncing off the walls, filling up every particle of air in the place. It’s that voice that’s woven itself deep into modern culture, in McKellen’s blood-hot, dexterous handling of Richard III, Gandalf, or X-Men ’s Magneto. It’s all-encompassing in that way. And it’s put to beautiful use in The Christophers , Steven Soderbergh ’s equally entertaining follow-up to last year’s double punch of Presence and Black Bag . These films share a fascination with narrative efficiency. While that’s true of Soderbergh’s entire filmography , it’s especially relevant to the work he’s done since “retiring” over his frustrations with the industry. They’re lean meat through and through, but feel outsized in their conceptual ambition, sex appeal, and emotional intimacy.…