Just when you thought you had the nuclear end of the world more or less under control in Fallout 4, developer Bethesda is springing something new on you: a robot apocalypse to go in your post-apocalypse.

Okay, maybe it’s not so much a robot apocalypse as it is a robot supervillain situation, but there are definitely robots and they are definitely deadly in the upcoming “Automatron” add-on for Fallout 4. As the trailer above shows, it’s about a guy called the Machinist, who wears a goofy costume, and has a horde of robots out to murder folks in the already-pretty-murdery Commonwealth.

Probably the best news of the whole thing is that as you slag evil robots, you’ll be able to cobble together your own mechanized monsters to fight alongside you as you trash supermutants and flee in terror from the occasional dinosaur-like Deathclaw. You can even give your robot a lightning gun.

There’s more content coming for Fallout 4 that’ll expand things like your capabilities in building shantytowns for ungrateful Wastelanders in the coming months. Meantime, the Automatron content will be available on March 22 to the tune of $9.99.