Since I am bored. Here goes something:
The trailer begins with a eerie fog over the London city, and a ten years old girl is seen chasing a mysterious figure on the street. The camera shot reveals the girl's face and the girl turns out to be Katrielle Layton, the daughter of Prof. Layton. Then, the camera pans over to the mysterious figure, who is revealed to be Prof. Layton. Katrielle stop and asks where her father is going. Layton tips his hat with his left hand and a Smash invitation letter can be seen in his right hand as he later begins to walks away. Katrielle who saw her father leaving, once again tried to chase him, but couldn't catch up. This sequence of event turns out to be a dream, and she is shown to be waking up from this dream. There was a morning montage of Katrielle's routine in her apartment before she took her bicycle and arrives at her detective agency. A Smash invitation letter can be seen attach to her office door, and she took the letter and found out this letter is addressed to her father. Since Prof. Layton went missing at this point in the story, Katrielle decides to takes her father's spot and becomes the Smash fighter in her father's place. A bunch of Smash gameplay montage is shown with her fighting against the other fighters and some references to the Layton series can be found during this gameplay. Lastly, the gameplay montage ends with her final smash, and before the trailer is finished, Katrielle utters her signature catchphrase, "the truth is always stranger than fiction".