From: Elementary ep. 5.18
Character Name/s: Black Peter, John Neligan
Reference: “The Adventure of Black Peter” (canon original) shares a few components with this ep: 1) there’s a pirate called Black Peter; 2) some of the evidence in the central murder case involves blade strikes strong enough to go through the body, implying a very strong arm. In the story, the body is pinned to the wall with a harpoon. In the ep, it’s deep sword stabs. (Also: remember the scene in Sherlock ep. 2.2, with Holmes coming home, blood-covered, harpoon in hand? That’s nearly directly from the original); 3) a subplot involving a log book and someone named John Neligan, intertwined w the murder scene but not a cause nor an effect.