Julie Fanshawe is a 35-year-old British musician with a largely unsuccessful career. He and his wife Elsa primarily survive on a meager monthly allowance by Julie's wealthy uncle Ernest. Decades ago, Ernest was given full administration of the Fanshawe family estate with the understanding that Julie would eventually get his share. Ernest mostly decided to never share the administration with a nephew which he views as incompetent. Julie is also habitually belittled by his mother-in-law, a retired musician. At some point, Julie's family and associates start having encounters with two different versions of Julie. The typical meek and mediocre Julie, and a bold, charming but ruthless version that goes by the name of David (the name of Julie's deceased twin brother). As David starts exhibiting criminal behavior, everyone starts wondering if Julie has an evil twin, or whether Julie has a split personality. After uncle Ernest is murdered within his own office, suspicions fall on either of his two nephews.