Vanessa Redgrave has joined the cast of Christoph Waltz’s crime drama “Georgetown,” which Cornerstone Films will debut to international buyers at the Cannes Film Market.

The Oscar-winning Redgrave plays Elsa Brecht, a wealthy widow seduced and married by eccentric social climber Ulrich Mott, played by Waltz, who has two Academy Awards to his name and is making his directorial debut with “Georgetown.” Together, Brecht and Mott, who was three decades younger than his wife, came to dominate political social circles and local gossip in Washington by throwing lavish events at their townhouse in the fashionable suburb of Georgetown.

When Elsa is found dead just hours after a dinner party, Ulrich immediately becomes the chief suspect, having always been perceived as a con man by Elsa’s daughter, Amanda, a federal judge. Amanda begins her own investigation as Ulrich creates an increasingly elaborate charade to convince everyone that unknown dark forces from his past are responsible for his wife’s murder.

“Georgetown,” written by Pulitzer Prize-winning author David Auburn, is inspired by the true story of Albrecht Muth, who was convicted in 2011 of murdering his much older socialite wife in Washington. Waltz first became attached to the project, which will shoot in Montreal this summer, in 2015.

Brett Ratner and David Gerson will produce the film for RatPac Entertainment alongside Andrew Levitas of Metalwork Pictures, which is also financing. Len Blavatnik will serve as executive producer for RatPac.

“Christoph is one of the most acclaimed actors of our generation, and I was greatly inspired by his vision in bringing David Auburn’s phenomenal script to the big screen,” said Ratner. “I really believe in Christoph as a filmmaker and I am thrilled to be producing his directorial feature debut.”

Redgrave has been nominated for an Academy Award six times, winning best actress for her lead role in 1977’s “Julia.” Waltz won best supporting actor Oscars for back-to-back Quentin Tarantino films “Inglourious Basterds” and “Django Unchained.”

Cornerstone Films is handling international sales and distribution on “Georgetown,” with ICM selling U.S. rights.