The first teaser spot for Guillermo del Toro’s FX horror series The Strain is now online, but you’ve probably already seen it. The spot premiered during the mid-season finale of AMC’s The Walking Dead, but its content was intentionally vague in the hopes of sparking up a conversation. Remember the “found footage” video of hordes of rats crowded the city sidewalks? Yep, that’s for The Strain.

The Strain stars Corey Stoll, David Bradley, Mia Maestro, Sean Astin, and Kevin Durand. Carlton Cuse will step in as showrunner while del Toro remains onboard as an executive producer. Hit the jump to watch the teaser.

Check out the teaser spot for The Strain below (via Bleeding Cool):