Wizards of the Coast
Core Set 2020, the 19th Magic: The Gathering core set, will be released this July but Wizards of the Coast haven't revealed a lot about it yet since the company is currently focused on marketing Modern Horizons. However, a Magic distributor has revealed the image of the Core Set 2020 booster box design and its artwork features Chandra going against a ghost. Check it out:
It looks like the story for Core Set 2020 will involve Chandra somehow but Wizards of the Coast haven't revealed details about the upcoming set. Core sets usually lack a central theme and story elements but that could change this year.
Core Set 2020 is set to be released on July 12, 2019.