Vin Diesel has hinted that will be the upcoming Marvel movie "The Inhumans," which is slated for March 2018.

The actor posted a picture on Facebook wearing a shirt with "The Inhumans" logo in front of the words "Are you Inhuman?" The picture comes a few months after the actor first posted another picture with a similar hint. 

That picture showed Diesel as Groot, the character he portrays in "Guardians of the Galaxy." In the caption the actor wrote, "Vin and Marvel...You all made it Happen! I get the strange feeling that Marvel thinks I'm Inhuman... Haha." 

These clues could be merely speculation, as no casting or details have been revealed. However, there are rumors that suggest that Diesel might play Black Bolt, the Inhuman king, who rarely speaks because his voice has the power to shatter mountains. 

It could also suggest Diesel is campaigning to be in the "Inhumans" film and portray another Marvel character. It could also suggest Diesel's Groot could show up in the film, especially since Marvel likes to unite their characters in their film universe. Groot was also one of the most beloved characters of "Guardians of the Galaxy" and most popular.  

The Inhumans film is based on the originally created comics by Jack Kirby. The comics were created in the 60s and were recently introduced to the Marvel Cinematic Universe via the presence of the superpower-inducing Terrigen Mist in this season's "Agents of S.H.I.E.L.D." mid-season finale. 

The film is slated to be released in 2018, so there is still a lot of time before anything is revealed. Currently, Marvel is working on the second Avengers film, "The Avengers: Age of Ultron," which is due in the summer, and "Ant-Man," which is slated to be released in July and will start yet another cinematic franchise. The company is also working on the third installment to "Captain America" and will also release a "Doctor Strange" movie, which is slated to star Benedict Cumberbatch. Meanwhile, the company will release the third "Thor" film and will also start the "Black Panther" series. 

Marvel will wrap up the third phase of Avengers films with the third installment to "The Avengers." That film is slated for 2018 and 2019 as it will be divided into two films. 

Marvel has had great success ever since it started releasing films in 2008 with "Iron Man." The company had its biggest hit in 2012 with the first Avengers film. That movie made $623 million domestically and over $1 billion worldwide.   

This past year the company also had one of the most successful years with "Captain America: The Winter Solider." The film went on to gross over $714 million worldwide and also scored rave reviews. Meanwhile, "Guardians of the Galaxy" was the surprise of the year. The film, which was based on a little-known comic, made over $772 million worldwide and became the top grossing film of the year. It also scored rave reviews and made multiple Top 10 lists. Marvel is planning a sequel, which is slated for May 2017.