Just Cause 3's next chapter of insanity, Mech Land Assault, will be available June 3rd for those with the season pass, and June 10th for everyone else. In a post on the game's official Facebook page, it is described thusly:
MECH LAND ASSAULT takes Rico Rodriguez to the new island of Lacrima, home to an abandoned eDen research base and a prison camp run by the mysterious Black Hand. Defended by huge powerful Mechs, Rico will need the new Bavarium Power Core rifle to disable their shields and hijack them. Once inside, Rico can use their powerful cannons and the GRIP Gravity Guns to hurl and smash the enemy into pieces.
In addition, you'll be able to bring these two types of mechs back to Medici, call in mech support from your allies, earn mech skills, use the new Bavarium Power Core rifle, and more.
The DLC will cost $11.99 / €11.99 / £9.49.