The Final Fantasy and Tomb Raider publisher is teasing something on Twitter.

Square Enix has revealed on its Twitter account that it is debuting an “exciting announcement” tomorrow. We don’t know what it’ll be about, but Square Enix is one of the biggest publishers in the gaming world, creating software for console, PC, and mobile. The mobile side includes a partnership with Mobile Strike and Game of War maker MZ, which Square Enix has tapped to make a massively multiplayer online mobile game based on Final Fantasy XV. We haven’t heard much about that project since Square Enix announced it last November.

Square Enix is the publisher behind popular Japanese role-playing series like Final Fantasy, Kingdom Hearts, and Dragon Quest. Last year’s Final Fantasy XV was the 10th best-selling game of 2016 in the U.S., according to The NPD Group, despite coming out late in the year.

Square Enix also publishes many Western series that it picked up after purchasing Eidos in 2009, including the Tomb Raider, Hitman, and Deus Ex franchises. The company has also expanded efforts on mobile, making games based on its properties like Deus Ex Go and Final Fantasy: Brave Exvius.