Of all the criticisms one might level at the films of Xavier Dolan, dullness is unlikely to be among them. Until now, perhaps: “The Death & Life of John F. Donovan” isn’t just flat, it’s choppy and grandiose. From its contrived structure to its forced speechifying, this story about a yearslong correspondence between Donovan (Kit Harington), a closeted actor, and Rupert (Jacob Tremblay), a troubled prepubescent boy, never acquires the emotional potency or coherence its themes demand.

Which isn’t to say it’s a chore to watch — far from it. The soundtrack, spiked by Adele and Florence and the Machine, is aces and the cinematography is often quite lovely. The strain comes from a framing device that has the adult Rupert (Ben Schnetzer), now an openly gay actor, laboring to persuade an eye-rolling journalist (Thandie Newton) that his book about the correspondence isn’t celebrity fluff. Rather, it’s a treatise on truth, identity and the life-altering power of fame, at which point it feels as if we’re the ones Dolan is trying to convince.