5. Lesser Evils

Complete story — includes the ending

While doing research in the hospital morgue, Sherlock stumbles upon a murder that no one else noticed. Someone with medical knowledge is poisoning pain-racked, near-death patients with epinephrine and making it look like they died of natural causes. He murdered eight others. The killer becomes acquainted with his victims; one of them spoke only Ukrainian. None of the doctors do, but a janitor was a doctor in Ukraine. The man is arrested and confesses to everything, but Sherlock is bothered by the fact that one of his victims was recovering. It turns out that her surgeon tampered with her medical file to make it look like she was dying. While operating on her, the surgeon left a surgical clamp inside her; because of his prior blunders, he would have been fired and in danger of losing his license if this mistake was known. Meanwhile, Joan reconnects with a doctor friend. While sitting in on a pre-op procedure, her gut instinct tells her that the patient has a condition that might kill her during surgery. Joan discovers she may be "a better doctor than she is a friend" after ordering a second, more accurate test (which confirms her suspicion) without her friend's approval.