Checkmate! Ludwig Solves a Murder with a Game of Reverse Chess

By his own admission, Ludwig is “quite the legend” in the puzzle-making field. But he has one puzzle — reverse chess — that never quite took off. “Nobody could ever solve them,” Ludwig laments. But finally! Finally! Reverse chess gets its moment to shine in Ludwig's fourth episode. In this game, the player doesn’t try to anticipate the next move their opponent will make in a chess game. Instead, they try to figure out all the moves their opponent has made before.

Lucy is begging her brother-in-law not to solve any more murders and to focus on discovering what happened to James and decoding the cipher James left behind. “The cipher is a puzzle. Solving puzzles is literally what you do,” she tells him. But every time Ludwig thinks he’s out of the murder-solving business, they pull him back in.  A man named Marty (Robert Jarman) has fallen to his death at a construction site. Once again, Carter is convinced that no murder has taken place. “It’s most certainly a workplace accident. Let’s just get it over with and get back to the station,” he tells Ludwig. But, of course, if it were just a workplace accident, there wouldn’t be an episode now, would there?

Ludwig notices several inconsistencies at the site. The warning signs were put up late. The generator had been completely tampered with. The guard rails had been loosened, and the generator, which was covered with water, had been rewired. Furthermore, an empty water bottle has been thrown down the chute and into the trash.