Catching up with Benedict Cumberbatch at the Toronto International Film Festival is a bit of a sprint.

He’s here with a cluster bomb of rich performances in three prestige films: an Internet rebel in “The Fifth Estate,” a plantation owner in “12 Years a Slave” and an emotionally unsettled grown son in “August: Osage County.” Besides making room in a packed schedule to chat about the quintessential Cumberbatch characters, he’s also being followed by rabid fans, which he’s charming enough to acknowledge is still “a bit thrilling,” and rampant rumors.

It was his brilliantly deft handling of a modernist Holmes in the BBC series “Sherlock” that brought Cumberbatch the first wave of serious attention. It’s a vocal, radical, international group of fans and the actor finds himself amused that anyone is all that interested in “how I behave, who I’m behaving with.”

Only a day into the fest, word surfaced that he’d traded the high-end horror of “Crimson Peak” to step into the lead in the Amazon intrigue of “Lost City of Z” for Brad Pitt. Meanwhile, the will-he-or-won’t-he Sith Lord question continues to circle. A “Star Wars” studio source I bumped into said, “definitely not.” But then “definitely not” was the party line on Khan, so I hold on to the hope that we might see a lightsaber in his hands.

I say that because Cumberbatch is so very, very good at being bad. “Maybe it’s that I bring good to the bad,” he laughs, settling in for a conversation about Julian Assange, the WikiLeaks founder at the center of “The Fifth Estate” — a role that’s tossed Cumberbatch’s name into the Oscar race. The film is scheduled for wide release Oct. 18 (subject to change).

For a time this year, the actor’s re-engineering of the genetically amped-up Khan in “Star Trek Into Darkness” stood as possibly his best use of extreme measures. A man unhinged by his own unique abilities, as Cumberbatch put it.

Constructing the flaws in specific terms, the actor believes, is some of the most important prep work he does. He’s always searching for the humanity in even the worst of the lot.

“I try to find why the actions may have a point, so people can at least see or empathize with the intentions or motivations,” the 37-year-old British actor explains. “With Khan, he’s a terrorist. But one man’s terrorist is another man’s freedom fighter.”

Which is, in a sense, exactly how one might think of Assange.

Cumberbatch absorbs the essence of the WikiLeaks founder so completely in “The Fifth Estate” you half expect him to show up with that startling shock of white hair, that haunted, hunted look.

He doesn’t, of course. He’s back to a rich auburn that is natural and the close-cropped style he favors. On this day, in fact, Cumberbatch is a study of warmth.

There’s a warm smile, easy laugh, and literally a glow when he talks of mum, dad, his childhood, his friends, all the things that keep him grounded while he’s moving at dizzying speeds on the professional front.

The son of actors, Cumberbatch began his own tour of duty on stage around 8, a creative outlet for his excessive energy.

In “Fifth Estate,” Cumberbatch’s task is to do to Assange what Assange did to corporations, governments and institutions: expose what’s behind the public face.

Though the movie has its issues, Cumberbatch has never been as artful in revealing the calculations of an uncommon mind.

The actor sees Assange as more antihero than villain — a serial interrupter of the status quo, opening one can of worms after another, WikiLeaks his bully pulpit.

“What we see is a very strong front man for a very powerful, complex cause,” Cumberbatch says. “There’s reams of footage of him arguing, defending, debating his position and then, did you see the John Farnham video?”

He’s referring to Assange’s parody of the Aussie pop singer — a YouTube sensation the moment it landed in late August. It features Assange in a mullet belting out the Farnham hit “You’re the Voice.” “There I was struggling to give the man integrity and there he was — and I was thinking ‘Oh my God.’”