After its launch back in October, Back 4 Blood is finally getting its first major expansion, and developer Turtle Rock Studios has given us the Ridden-filled details in a new trailer.

The DLC is titled Tunnels of Terror and will not feature a brand new story that fans may be traditionally used to with the Left 4 Dead series. Instead, there will be Ridden hives — seven of them, in fact — that will serve as underground dungeons that we cleaners will scour through. That being said, it is unknown whether or not there will be a continuation of the story with these new dungeons; they just won’t be structured the same way.

On top of the new levels, there are two new Cleaners coming to the crew: Sharice and Heng. Sharice has a history as a firefighter and her specialties lie in armor plate buffs, trauma resistance, and team health. Heng, on the other hand, has sensory abilities as a former chef that will help out the team.

With new Cleaners comes new Ridden, and there are three new kinds that players will have to deal with, including the Urchin, Shredder, and Ripper. The trailer does not go into exact details as to what special abilities these Warped Ridden have, but it looks like the Ripper does a ground pound that sends an outward wave attack. Additionally, the Tunnels of Terror DLC will include new gear, weapons, and cards when it releases on April 12.