A mainstay of the London art scene since his starry breakout in the creative explosion of the 1960s, Julian Sklar (Ian McKellen) has drifted into a cluttered, self-imposed seclusion. His two estranged children (James Corden, Jessica Gunning) enlist Lori (Michaela Coel), a young painter and sometime-forger, to pose as a prospective assistant and gain access to a fabled series of unfinished canvases Julian has buried deep in his home studio, in a deceptive bid to secure an inheritance for themselves.