Katrielle and the Phantom Thief of the Century is the fourth episode of Layton Mystery Detective Agency: Kat's Mystery-Solving Files.


Case ExplanationEdit

Inspector Hastings was conducting a police investigation, a jewel has been stolen by Phantom Thief Seine. So The inspector enlists the Agency's aid in tracking down a serial jewel thief before the criminal can enact their most daring heist yet, the Goddess’ Smile diamond at the British Museum.

Seine's Past VictimsEdit

So far, Seine has stolen everything he has wanted to, the police have no idea how he's done it, what he looks like, or even Seine's gender. Katrielle starts gathering evidence from Seine's past victims and notices some moss in a weird place, mold spots and puddles even though there’s been no rain.

British MuseumEdit

When the day of the thieving arrives, Hastings visits Katrielle and informs her of another clue. A small child visited the police station recently about something terrible that was going to happen, but they sent him home without hearing what he had to say.

On the way to the museum, a van drives by carrying a huge amount of ice, they will be used for cooling down computers at a computer club. One of the members, Bengali, the same boy who visited the station, has a super computer.

Case SolvedEdit

Katrielle figures out the puzzles and runs after the van to where the computer club is. The mastermind behind Phantom Thief Seine was Bengali. He worked with a jaybird who would steal the gems for him so he wouldn’t have to leave his room through a ludicrously complex method. That method is making an ice ball that would bounce on a fountain to knock a plant over causing a cat to sneeze and wind to blow a newspaper on the door of the museum. However, he only did this so that an area would be sectioned off where a ground subsidence occurs as they talk and no one is hurt. Due to this deed and the fact that Inspector Hastings realized they never listened to him when he came to report the ground subsidence, he lets him go.



  • Moss
  • Mold spots
  • Puddles without rain
  • Small child's warning
  • Bengali's super computer


  • Katrielle compares this episode's case to the shiny fruits covering tart cream; "it tastes just like a fruits tart".
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