Poor, poor He-Who-Must-Not-Be-Named. It’s OK, You-Know-Who. Daniel Clarkson is on your side.

“I feel Voldemort is very misunderstood,” Clarkson says. “Here he is, the greatest dark wizard of all time, and he keeps getting beaten by an 11-year-old. That’ll hit you pretty hard.”

Clarkson plays Lord Voldemort (among others) in “Potted Potter,” a 70-minute, two-man comedic crash course that covers all seven Harry Potter books. A fellow Brit, Jefferson Turner, plays Harry; Clarkson is Hagrid, Hermione and “pretty much everybody else.”

The show started in 2005 as a five-minute street performance summarizing the first five novels, created to entertain people waiting in line for the release of “Harry Potter and the Half-Blood Prince.” The current incarnation was born in 2007, when the duo managed to get elements of the seventh book, “Harry Potter and the Deathly Hallows,” wedged in just days after its release.

Clarkson says he’s the bigger Harry Potter fan of the duo, but his stage persona lacks a lot of fundamental knowledge. “It’s that straight man/dumb, funny man act, with me trying to get through by the skin of my teeth, but not knowing Harry Potter from ‘The Lord of the Rings’ from Narnia,” Clarkson says.

The show is billed as appropriate for “ages 6 through Dumbledore,” which Clarkson says was intentional. “First and foremost, Harry Potter is for everybody. I don’t think there’s another series like it,” he says. “When we do the show, it’s an eclectic mix. We’ve had a bachelorette party [sitting] behind an 8-year-old’s birthday party.”

While Turner and Clarkson refer to the movies in the play, they stick to the books as their source material, with a little poetic license. “When I read the books years ago, in my head [Severus] Snape had an Eastern European accent,” he says. “There’s nothing that suggests that in the book, but I think that brings out the evil in him.”

So Clarkson’s interpretation of the morally ambiguous Hogwarts professor (he ills-kay Umbledore-day, but is edeemed-ray) is entirely unlike Alan Rickman’s defining film performance. There’s another big difference, too.

“Alan Rickman only got to play Snape,” he says. “I get everybody.”

Shakespeare Theatre, 610 F St. NW; Thu.-Sept. 15, $45-$75; 202-547-1122. (Gallery Place)