Sometimes the closer you are to the truth, the harder it is to see. pic.twitter.com/m13w9aqvSH— Layton Series (@LaytonSeries) June 18, 2019
As seen above, the official Professor Layton Twitter account is teasing some sort of news concerning Professor Layton and the Diabolical Box. The image above is a Molentary Railway Express ticket, which is the name of a train in Diabolical Box. There was an HD version of the game released on smartphones in Japan awhile back, but it never saw stateside release. This could be for a localization of that project, or perhaps something new altogether.