The Ancient Gods is the first DLC for DOOM Eternal
Kicking off QuakeCon At Home, Bethesda and Id Software have released a teaser trailer for the first expansion for DOOM Eternal, called The Ancient Ones, and all we know so far is that by saving humanity the delicate balance of power in the heavens has been altered.
The expansion will get a full reveal as part of Gamescom Opening Night Live, which is about three weeks away. If you own the season pass, when the expansion is released, you will get it for free then, else you will have to buy it on its own.