Layton's Mystery Journey: Katrielle and the Millionaires' Conspiracy is the seventh mainline game in the Professor Layton series. It follows Katrielle Layton, the daughter of Professor Layton. With the help of her friend Ernest Greeves and a talking dog named Sherl, Kat solves various smaller mysteries in London in the hope of finding her missing father.

The game was officially revealed on July 27, 2016, during LEVEL-5 Vision 2016[4]. The name "Lady Layton" was already leaked the day beforehand due to a leaked trademark of LEVEL-5[5].

The puzzles in the game are designed by Kuniaki Iwanami, due to the passing of Akira Tago.

Before the game's release, it was being promoted through an ongoing campaign, which had people solve puzzles in the real world all around the globe. During this campaign, it was possible to obtain items that could be transferred to the actual game once it was released.

Layton's Mystery Journey: Katrielle and the Millionaires' Conspiracy was released for Nintendo 3DS, iOS, and Android in 2017, and a Nintendo Switch port, titled Layton's Mystery Journey: Katrielle and the Millionaires' Conspiracy DX, was released in Japan on August 9, 2018.

Gameplay Changes Edit

  • On iOS/Android, since the entire screen is touch sensitive, including the "top" screen, you can simply tap the places to investigate directly, instead of moving the magnifying glass over to it.
    • This is similar to how the Professor Layton games worked on the Nintendo DS.
    • The magnifying glass from the 3DS games is also still present; allowing the player to choose between both styles.
  • You can now revisit previous cases at any time.
    • Once a case is solved, revisiting it will show how many puzzles are left to solve and how many hint coins are left to find. The map will also highlight all locations where everything has been solved/found.
    • Some puzzles will only appear after the case has been solved.
    • Due to this mechanic; it is now impossible to miss any puzzles. As such, Granny Riddleton is now a regular character; though she still occasionally gives a puzzle of her own.
  • Multiple cases may unlock at once, and can be solved in any order.
  • Some spots now hide ten hint coins instead of just one. If one of these spots is tapped, all coins will fly out simultaneously as a fountain.
  • Picarats will now be removed for up to four incorrect answers, instead of two.


Major Characters Edit

The Seven Dragons Edit

Minor/Recurring Characters Edit

Puzzles Edit

See Layton's Mystery Journey: Katrielle and the Millionaires' Conspiracy/List of puzzles

Downloadable Content Edit

# Item Price[n 1]
1 Dating Dress & Puzzle €1.89/$1.99
2 Equestrian Ensemble & Puzzle €1.89/$1.99
3 Cardinal Cape Coat & Puzzle €1.89/$1.99
4 Monotone Minidress & Puzzle €1.89/$1.99
5 Retro Refit & Puzzle €1.89/$1.99
6 Sky-blue Statement & Puzzle €1.89/$1.99
7 Pleated Pleaser & Puzzle €1.89/$1.99
8 Denim Daily & Puzzle €1.89/$1.99
9 Imperial Elegance & Puzzle €1.89/$1.99
10 Picnic Blanket Wrap & Puzzle €1.89/$1.99
11 Daddy's Girl & Puzzle €1.89/$1.99
12 Luke Lookalike & Puzzle €1.89/$1.99
13 Emmy Impersonation & Puzzle €1.89/$1.99
14 Anton-ish Attire & Puzzle €1.89/$1.99
15 Aurora Again & Puzzle €1.89/$1.99
16 Floral Finesse Free (3DS)
17 Professor Layton cushion Free (3DS)
Total (if bought individually) €28.35/$29.85 (mobile app version)
$9.95 (For #11-15 in the 3DS version)
Kat's Clobber & Puzzles Set (1-10) €16.99/$22.46
Kat's Cosplay & Puzzles Set (11-15) €7.49/$7.99
Total (if bought as packs) €24.48/$32.37 (mobile app version)
$7.99 (For the Cosplay Set in the 3DS version)

Cases Edit

  1. Prologue: Lady and a Tramp
  2. Case 1: The Hand That Feeds
  3. Case 2: Murder on the Thames
  4. Case 3: The Stolen Kiss
  5. Case 4: Pet Pandemonium
  6. Case 5: Ghost Busted
  7. Case 6: An Unexpected Windfall
  8. Case 7: Ratman Returns
  9. Case 8: The Goddess of the Thames
  10. Case 9: The Battle of Hastings (Originally: Hastings Off the Beat)
  11. Case 10: The Importance of Being Ernest
  12. Case 11: Katrielle Layton: WANTED!
  13. Case 12: Diamonds Aren't Forever (Originally: The Million Pound Puzzler)

Museum Edit

See: Layton Museum

This is the page that shows what you can unlock with points from the museum.

Plot Edit


Prologue: Lady and a Tramp Edit

Private detective Katrielle Layton, daughter of the famous Professor Hershel Layton, awakens from a nightmare about her missing father on the day of her detective agency's opening. The same day, Katrielle and her assistant Ernest Greeves meet a talking dog that, for reasons unknown, cannot be understood by anyone else but them. The dog explains that he has amnesia, and that he wishes for them to solve the mystery of who he really is, and Katrielle makes up the name "Sherl O.C Kholmes" for him.

Case 1: The Hand That Feeds Edit

One of the hands of Big Ben has gone missing and Inspector Hastings calls upon Katrielle's aid to solve the case.

Case 2: Murder on the Thames Edit

London's "Riverside Festival", a special event where two lovers confess their love to each other on opposite sides of the River Thames, is underway. However, right before the last day of the event, two such lovers meet an unnatural death right after confessing in a manner connected to the mysterious legend that started the event in the first place.

Case 3: The Stolen Kiss Edit

Ernest tells Katrielle and Sherl that he has won some tickets for a movie premiere in the nearby Saveloy Theatre. Katrielle and Ernest decide to attend; but just as the movie is about to reach its climatic kiss scene, it turns out the scene has been stolen!

Case 4: Pet Pandemonium Edit

Madame Gretchin Doublée asks for the help of Katrielle to find her pet Rex, who has seemingly disappeared.

Case 5: Ghost Busted Edit

Katrielle is invited by Liza Wight to her residence to investigate on ghosts that appear to be haunting the mansion.

Case 6: An Unexpected Windfall Edit

The Layman's Reserve bank, owned by Grant Sloanes, has been robbed of one hundred million worth of paper notes. They enlist the help of Katrielle to find out the culprit.

Case 7: Ratman Returns Edit

Katrielle is asked by Taboras Lloyd, the chief editor of the London Times, to investigate the mysterious disappearance of Ratman, a local superhero.

Case 8: The Goddess of the Thames Edit

As a thanks for their previous help, Katrielle, Ernest, and Sherl are all invited on a luxury cruise on the Thametanic. Once aboard, the owner of the ship, Mustafa Fullhold decides to entertain the guests with a treasure hunt around the ship where they have to find little statues of the Goddess of the Thames. But when the main prize, a fully sized golden statue worth millions, goes missing, Katrielle is tasked with finding it back.

Case 9: The Battle of Hastings Edit

On Godwin's day, a local holiday, Katrielle is enjoying a day without work. Suddenly, Inspector Hastings enters the Detective Agency and tells Katrielle that it is his wife's birthday and that he forgot all about it, and begs Kat to help him find a suitable present despite every shop being closed.

Case 10: The Importance of Being Ernest Edit

Sherl is having a talk with Ernest about why the latter is so willing to work for Katrielle despite not being paid. Ernest then tells him the story of when he once was accused of theft, and how Katrielle managed to prove his innocence.

Case 11: Katrielle Layton: WANTED! Edit

Katrielle is accused of murdering Clover Pryce and it is up to her to clear her name and catch the real killer.

Case 12: Diamonds Aren't Forever Edit

Layton and the Seven Dragons are invited by the mysterious Lord Adamas to the abandoned mansion of Lord Maximilian Richmond, a millionaire who died 10 years before. In the occasion, Adamas forces the Seven Dragons to sign a contract where they relinquish all their fortunes to him should they fail to solve a series of puzzles, or he will reveal a grave secret about them. Attending the event at Layton's stead, Katrielle accepts Adamas' request to oversee the dispute. All of the Dragons fail to solve the puzzles and accept defeat, until Katrielle discovers that Lord Adamas is no other than Ernest, whose true identity is Miles Richmond, Maximilian's grandson, who grew up with the false assumption that the Dragons betrayed and ruined their family, swearing to enact revenge on them. After the misunderstanding is cleared, Ernest reconciles with the Dragons and accepts Katrielle's request to keep working as her assistant.

In the post-credits, Katrielle renews her vow to unlock the mystery of Sherl's true identity and discover the whereabouts of her father. Although she is no closer with the latter, she proclaims that she has solved the puzzle that her father left behind when he disappeared: "If you're not really my child, then who exactly are you?".


Main article: Gallery:Layton's Mystery Journey

Trivia Edit

  • Akihiro Hino (LEVEL-5 CEO) stated in a Famitsu article that LEVEL-5's reason for creating a female protagonist was because more than half of all players of the Professor Layton series were female, and selected a female protagonist to appeal more to players[6].
    • Additionally, the reason for a new protagonist over Hershel Layton was because of an belief that the Layton series had strayed from its roots in recent previous entries, which featured "overblown" stories like saving the world, and a desire to bring the series back to its core principles. This resulted in going from Hershel to having his daughter as the protagonist, as the team felt that they can't "bring back a guy who's saved the world and have him go do things like find a missing cat".
  • The game contains a glitch where the play time will suddenly display "99 h 59 min" of play time. If the game is saved when the glitch occurs; the save screen will show the time as either "0:00" or completely blank.
    • In some cases, fully quiting the game and reloading the glitched save file will restore the proper time. Some people have also managed to restore their times by uploading it to the LEVEL-5 ID service and re-downloading it.
    • It is unknown what causes this glitch to happen.
  • The 3DS version of the game does not have any 3D effects, unlike most 3DS games. Adjusting the 3D slider on the system has no effect.
  • This is the first Layton title to be released on the Nintendo Switch.
  • The second case, Murder on the Thames, shares a name with Annie Dretche's famous mystery novel.

External LinksEdit


  1. ^ Prices may differ according to region; even with the same currency.


  1. ^ Layton's Mystery Journey 3DS release confirmed for October 6 in North America - Nintendo Everything
  2. ^ The renowned Layton series returns to Nintendo 3DS as LAYTON'S MYSTERY JOURNEY™: Katrielle and the Millionaires’ Conspiracy launches on 6th October - Nintendo UK
  3. ^ a b Layton’s Mystery Journey, formerly Lady Layton, launches for 3DS in Japan and smartphones worldwide on July 20 - Gematsu
  4. ^ New Titles Announced at “LEVEL-5 Vision 2016: New Heroes” Event - LEVEL-5 International America
  5. ^ New Level-5 trademarks include 'Lady Layton,' two more Yo-kai Watch games - Destructoid
  6. ^ Lady Layton: why the protagonist is a woman, game structured like a TV series - Perfectly Nintendo
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