The police find a body in the middle of the street. Mac and Stella investigate Flack says the man is Martin Stafford a CEO for a software company. They discover he is drenched in his own blood. Sheldon imagines the man tell him he could have saved him. Sheldon says he bled out through the nose mouth and ears. Stella says Martin was dizzy and stepped erratically. They wonder if Martin was poisoned.

At the station, Mac sees that is upset. Sheldon says he made a mistake and might be responsible for Martin's death. Sheldon explains he examined Martin when he was working his day job. He remembers meeting Martin at the park while he was with a young woman. He saw that Martin was bleeding from the nose and thought it was nothing since he smelled he was drinking. Sheldon says he scolded him then sent him off. Sheldon says he can't figure who the woman is. He regrets not taking Martin to a hospital right away, but Mac tells him they should just move forward and solve the murder.