Outside the interrogation room, Gregson praises Holmes. Holmes is freaked out that the janitor is telling the truth about Samantha Cropsey's condition. He doesn't care that they've caught the Angel. There's more to do! And a good thing, too, because we're only 45 minutes into the show.
Holmes sits cross-legged in the brownstone, studying files. Watson proposes sushi for dinner, so Holmes lists diseases related to raw fish. He's trying to determine why their Angel got Samantha wrong. The door buzzes and it's Carrie. He calls her "Joanie's friend," which is weirdly disturbing. Then when it's clear they're not going to have a conversation, Holmes shouts for Watson and strides off. Carrie is here to tell Watson she was right and that the third test revealed that Morgan did indeed have endocarditis. Some anonymous person put the test request in Morgan's file. Watson admits nothing and says Carrie was lucky. And that she knows what it's like not to be lucky. Carrie says, "You were always a good friend, Joanie. But you were a better doctor." And she leaves.
Holmes was listening in on the conversation (from five feet away) and praises her instincts: "Well done." And he's gotten an idea! "Get your coat!"
Gregson's office. And Dr. Baldwin! Holmes asks if he's brilliant. Baldwin allows as how some people call him that. Last night, Holmes realized he might not have been the first person to realize there was an Angel of Death in the hospital. But records show Baldwin did investigate the bodies of his two patients. Baldwin's defense is that they were his patients, so naturally he investigated their deaths. Holmes says he might have noticed the same thing he did. But Baldwin left a clamp in Samantha Cropsey's chest. Fixing that would have earned him his third strike. So he made Samantha an attractive patient for the Angel of Death. He forged the results of a cancerous discovery and put in her file. And then he lowered her pain meds to get the Angel's attention. Samantha has been exhumed, and the clamp was indeed in her rib cage. Baldwin speaks hypothetically and says that they may have just proved that he made a mistake, but there's no evidence of faked records. Well, Holmes checked out the janitor's records, which were very complete. Instead of copying out information, he took pictures of the official charts! And upon being presented with this evidence, he told them where they were hidden! Baldwin is sanctimonious. Gregson says it's Murder 2: twenty to life.