The story is set in London and follows Katrielle as she solves mysteries with her talking dog Sherl.
The best episode of "Layton Mystery Detective Agency: Kat's Mystery‑Solving Files" season 1 is "Katrielle and the Mysterious House", rated 6.4/10 from 8 user votes. It was directed by Kazuki Yokoyama and written by Akihiro Hino. "Katrielle and the Mysterious House" aired on 4/8/2018 and is rated 0.1 point(s) higher than the second highest rated, "Katrielle and the Devil's Dress".
Katrielle Layton, an intrepid investigator who heads up the three strong team at the Layton Detective Agency alongside her assistants Ernest and Sherl, takes on a case involving a mysterious house in which a new tenant's family suddenly and inexplicably disappeared.
Director: Kazuki Yokoyama
Writer: Akihiro Hino
Katrielle is approached by Pastel, a struggling musician, who claims that a strange dress he bought for his wife Olivia is causing her to become possessed.
Director: N/A
Writer: N/A
A young woman named Liv seeks Katrielle's help after she is visited by her late husband, Andy, apparently returned to life as a zombie.
Director: N/A
Writer: N/A
Inspector Hastings enlists the Agency's assistance in tracking down a serial jewel thief before the criminal can enact their most daring heist yet.
Director: N/A
Writer: N/A
The team becomes involved in a new case when a young man approaches the Agency in the hope of discovering a way to resume an implausible lucky streak.
Director: N/A
Writer: N/A
Katrielle stumbles upon a fresh mystery when a classmate of Ernest relates the story of a mysterious bus journey that seemingly transported them back to the time of their childhood.
Director: N/A
Writer: N/A
The Agency is visited by a young boy named Leo who fears that the mysterious hero of London's streets, Ratman, has been kidnapped.
Director: N/A
Writer: N/A
The team are summoned by Inspector Hastings to the site of a seemingly impossible burglary: one hundred million pounds have vanished from a high-tech bank vault.
Director: N/A
Writer: N/A
Katrielle is called to the estate of a millionaire gourmet with an unusual request: her pet has gone missing, and she wants it found before her dinner party commences.
Director: Tetsuaki Watanabe
Writer: N/A
Rosa, an old acquaintance of Katrielle's father, visits the Agency with information relating to the Professor's disappearance eleven years ago.
Director: N/A
Writer: N/A
The Agency attend the premier of a much-anticipated film, only to discover mid-scene that the moment of the climactic kiss has disappeared from the reel.
Director: N/A
Writer: N/A
Relaxing on a public holiday, the Agency team become embroiled in a highly unusual case when a desperate Inspector Hastings pleads their aid in finding a last-minute gift for his wife's birthday.
Director: N/A
Writer: N/A
Katrielle takes on a new case involving a young pianist who is being plagued by appearances of a doppelgänger.
Director: N/A
Writer: N/A
Katrielle and the team are left puzzled when Hastings requests their help on a case where the culprit has already been uncovered.
Director: N/A
Writer: N/A
The Agency receives a new mystery to solve when a young farmer details the unexplained appearance of strange patterns in their wheat fields.
Director: N/A
Writer: N/A
Katrielle investigates a young girl on behalf of her concerned mother, who believes her daughter is able to predict the future.
Director: N/A
Writer: N/A
Hastings turns to the Agency trio when London is menaced by a mysterious growling giant lurking in the fog.
Director: N/A
Writer: N/A
Travelling on board the Molentary Express for a special solar eclipse tour, the team find their attention divided when clients old and new describe a sequence of strange events.
Director: N/A
Writer: N/A
The team are summoned by a young heiress whose estate is seemingly being haunted by a host of ethereal apparitions.
Director: N/A
Writer: N/A
Rosa returns to continue her story, and reveals the link between Katrielle's origins and the Professor's disappearance.
Director: N/A
Writer: N/A
In search of sweets of legendary reputation, Katrielle is hooked when she is told that she will have to prove her connoisseur qualifications by locating the nearby store herself.
Director: Tetsuaki Watanabe
Writer: N/A
Katrielle is invited to the unveiling of Agency acquaintance and child genius Bengary's latest invention: Sketman John, a robotic renaissance-manservant.
Director: N/A
Writer: N/A
One of London's famous "seven millionaires" requests the team's investigative attentions after discovering a love letter written by his much-adored daughter, Allie.
Director: N/A
Writer: N/A
Hastings employs the Agency's efforts in the search for a hand belonging to Big Ben, in the hope of recovering it before the arrival of a foreign ambassador.
Director: N/A
Writer: N/A
Katrielle joins an investigation at London's Riverside Festival into a tragic incident that took place on the banks of the River Thames, mirroring a local legend.
Director: N/A
Writer: N/A