A lifelong rivalry between opera singer Renata Radleigh and her younger brother Don takes an unexpected turn when Don is accused of murder. He is Saint Louis Opera's star fundraiser after procuring a last-minute underwriter for its avant-garde production of Carmen. Don is accused of seducing his donor to get the contribution, then killing her after her husband finds out. His alleged victim, Dr. Helen Stromberg-Brand, had invented a vaccine that was expected to earn billions and win her a Nobel. The scandal shocks Saint Louis and pushes the opera company to the brink. No one cares about defending Don. Only Renata believes he is innocent. Her attempts to clear him lead to warnings of dismissal, threats of arrest, and a brutal assault. She finds an unexpected ally in Peter Lombardo, a former journalist who does PR at the medical center where Helen had made loyal friends and bitter enemies. Peter believes that the trail leading to Helen's killer begins with the vaccine, not the opera donation. Together they discover that the search for the next wonder drug can inspire greed and vengefulness beyond any opera plot. As their feelings for each other deepen and more corpses turn up, an onstage mishap elevates Renata to the role of Carmen. But the greatest moment of her career may be the last moment of her life.