"Does Jekyll know about Hyde?" asks serial killer turned writer Jack Unterweger before strangling a soprano with a brassiere. Though himself dead, Unterweger (played by an unnerving John Malkovich) has returned to tell the audience his story. Two singers, accompanied by the virtuoso early-music ensemble Orchester Wiener Akademie, perform live opera arias by Mozart, Vivaldi, Haydn, and others in an inspired counterpoint, providing both a soundtrack to and a deliciously ironic commentary on Unterweger’s disturbing confessions.