There’s a bit of a nod-nod, wink-wink irony in the title of Kenneth Branagh’s latest exploration of the genius of William Shakespeare. All Is True refers to the alternate title of Henry VIII, the Bard’s penultimate play, which was being staged in 1613 at London’s Globe Theatre when the playhouse caught fire and burned down mid-performance. That fire is a documented fact, one of the relatively few available about the historic figure who may be the most celebrated poet and playwright of all time, but yet left precious little evidence from which later generations could reconstruct his personal history.

This all sends Shakespeare moping around the Warwickshire countryside and his garden, like a 17th century version of Kurt Wallander (coincidentally, there’s also a mystery surrounding Hamnet’s death that he doggedly unravels). When he’s in town, self-righteous hypocrites heap scorn upon him for his humble origins and a slander lawsuit involving Susanna. The only saving grace comes in a visit from his longtime patron, Henry Wriothesley, Earl of Southampton, played by Ian McKellen in the film’s strongest sequence. As Will pours his heart out, he slides into Sonnet 29 (“When, in disgrace with fortune and men’s eyes . . .”), leveling a penetrating gaze at the noble benefactor who may or may not have been the “Fair Youth” to whom the first 126 sonnets were addressed. But Will’s ardor is deflected by Wriothesley’s reply: the earl’s own recitation of the same sonnet, a wiser, more nuanced rendition that leaves the poet with even more regret.

Directed by Kenneth Branagh. PG-13, 101 min. At Century Centre. Visit landmarktheatres.com for showtimes.