"The Strain" is moving forward with its narrative while setting all the chess pieces in place. The next episode is expected to hit some action beats as different groups make their move.

In the teaser trailer for episode 3 of season 4, Ephraim Goodweather (Corey Stoll) and Alex Green (Angel Parker) will try and eliminate a huge group of strigoi hiding out in an abandoned house. The strigoi are vampire-like, parasitic creatures ruled by The Master aka Eldritch Palmer (Jonathan Hyde).

Goodweather mentions that they will be "highly susceptible to poison," which hints that they might use some kind of gas to fill up the house and kill the strigoi. In the teaser, the human rebels are shown attaching a hose to a tank which possibly contains the poisonous gas.

In the previous episode, Goodweather was able to convince Green to attack strigoi targets with a higher profile like factories and buildings instead of buses and other small vehicles.

In the episode teaser, the other group led by Vasily Fet (Kevin Durand) is shown infiltrating an underground military base. However, they encounter some enemy forces in the process which will leave fans thinking how they would come out of it intact.

Zach Goodweather (Max Charles), the son of Ephraim, will also explore a love interest in the next episode. Due to his seclusion to the outside world by the Master, the cleaning girl from the first episode could serve as a distraction for the young Zach. However, the Master gives him the warning at the end of the teaser, "Of all the creatures in the natural world, the human animal is the most dangerous."

It is strongly hinted that Zach will have to make a decision in a future episode on which side he will choose: the humans or the strigoi.

"The Strain" season 4 episode 3 will hit the airwaves on Sunday, July 30 at 10 p.m. EDT on FX.