A teaser for 'The Strain: The Animated Prequel' explains the long, winding history of the Occido Lumen, an occult text with a bloody past. For all the evil it brings, however, this text may just be the last hope humanity has in facing the Strigoi.

Developed by Guillermo del Toro and Carlton Cuse from the bestselling horror trilogy by del Toro and Chuck Hogan, "The Strain" follows Dr. Ephraim Goodweather (Corey Stoll), whose team from the Centers for Disease Control is called upon to investigate a mysterious viral outbreak with hallmarks of an ancient and evil strain of vampirism. As the strain spreads, Eph, his team and a group of everyday New Yorkers wage war for the fate of humanity.

As the second season opens, New York City is rapidly falling to an evil epidemic, and no one is coming to its rescue. Eph and his unlikely allies tried to take down the embodiment of this evil — the Master — and failed. Now he and Dr. Nora Martinez (Mia Maestro) concentrate on creating a biological weapon to wipe out the creatures, while Abraham Setrakian (David Bradley) searches for an ancient book he hopes will reveal the strigoi’s entire history … and possibly a way to kill them.

"The Strain" airs Sundays at 10 p.m. ET/PT, beginning July 12, on FX.