The "Second Opinion" episode is the Season 5, Episode 1 of the TV show "Law & Order," which originally aired on September 21, 1994. This episode is notable as it introduces Jack McCoy as the new Executive Assistant District Attorney. The storyline centers on McCoy pursuing murder charges against a woman who provided questionable alternative treatments to women suffering from breast cancer. The episode explores themes of medical ethics, patient care, and the legal ramifications of medical decisions. It involves an investigation triggered by a woman's death and the release of toxic fumes from her body, raising suspicions of negligence or malpractice. The episode is recognized for its intelligent writing and takes a critical look at controversial medical treatments and their consequences in the justice system.