Hot tickets catch fire when stars switch-hit. Oh, for a time machine to take us back to 1935, when John Gielgud and Laurence Olivier were alternating as Romeo and his flashy buddy Mercutio in Gielgud’s London Romeo and Juliet. Peggy Ashcroft was on hand, too, as Juliet, alongside Edith Evans’s Nurse and the Apothecary of Alec Guinness—theater royalty, every one, though their titles of Sir and Dame would not come until later.

Fast forward to February 2011. After a string of films including Trainspotting and Slumdog Millionaire, Danny Boyle stages Frankenstein at the National Theatre, London. Two actors are onboard to share the roles of the hubristic “modern Prometheus” Victor Frankenstein and the brokenhearted “Creature” he has patched together from dismembered cadavers. Who will make the scarier monster, who the madder scientist?

In this corner: the Trainspotting alum Jonny Lee Miller, veteran of 30 years (he started young) on screens big and small. And over in this corner: Benedict Cumberbatch, TV’s smokin’ new Sherlock Holmes, the most withering ever. Live broadcasts on consecutive March Thursdays bring the battling matchups to movie screens worldwide. Fast forward to the present, and they’re available online, offering fans a chance to debate until Doomsday.

What goes around, comes around: “I have love in me the likes of which you can scarcely imagine and rage the likes of which you would not believe,” Shelley’s Creature cries in the novel. “If I cannot satisfy the one, I will indulge the other.” Cumberbatch on top this time, Miller fighting for air.

Compared with the young Mary Wollstonecraft Shelley’s ferocious novel of Romantic ideas, Nick Dear’s sketchy script scarcely rises to the condition of CliffsNotes. No matter. For the two principals (though not for the supporting cast), the outline carves out all-but-unbounded imaginative space. The Creature’s far larger and showier part opens with a tour de force of physical theater, in which he spills out of a pod for a tortured ten-minute solo, grunting, quaking, crawling, flailing, squinting, grimacing, until at last he can stand and walk—upright, yes, but rickety. Then strangers start throwing things and beating him up.

Ordinarily, both Cumberbatch and Miller executed this sequence without a stitch. For the cameras, they donned drab, threadbare loincloths, which in no way obscured the contrast between Cumberbatch’s hyper-flexible, high-mannerist physique and Miller’s, which is buff, foursquare, and stocky.

The temperamental contrast is equally pronounced. Cumberbatch is the diva—think Cleopatra, teasing every glance and syllable for the eccentric blue note. Whereas Miller is the regular bloke—a Caliban, moody at times, seldom fully in touch with his feelings, yet a stranger to stratagem, no player of games. Cumberbatch unravels even as he creates. All fire and air, he burns his candle at both ends, and when the light fails, there’s nothing to remember. Miller plays a more earthbound game, but when it’s over, the afterimage of his still, private despair lingers in the mind’s eye.

Perhaps paradoxically, Miller’s subliminal appeal to a viewer’s compassion is strongest in the lesser role of Frankenstein, who scarcely even puts in an appearance until half time. When Cumberbatch’s Frankenstein carries on about science, it’s a megalomaniac’s smoke and mirrors. Miller’s disappointed idealist is a man betrayed. Which actor gives the greater performance in which part or parts? Ask your heart, then ask your head, or vice versa.

Frankenstein is available for streaming on the National Theatre at Home Web site

Matthew Gurewitsch writes about opera and classical music for AIR MAIL. He lives in Hawaii