“The Strain” Season 3 began with an update on the FX horror series’ favorite characters. Episode 2 moved the plot forward with Dr. Ephraim Goodweather/Eph contemplating The Master’s deal to trade the Occido Lumen for his son Zack’s life.

However, before Eph (Corey Stoll) stole the book that is supposed to tell the reader how to destroy The Master (Jack Kesy) once and for all, half-human half-strigoi Quinlan (Rupert-Penry Jones) struck a deal with the CDC doctor – let him kill the Master during the exchange.

Meanwhile, last week’s episode gave an update on Dutch Velders (Ruta Gedmintas) who was, so far, cleaning New York of the blood-sucking vampires with her questionable group of friends.

Episode 3, titled “First Born,” will finally reveal the reason behind Quinlan’s thirst for revenge. Although it’s obvious he wants to kill The Master and is free from his power, it isn’t clear why.

Watch the promo to get a glimpse of what’s next on “The Strain” Season 3 below:

According to the synopsis of episode 3 (via SpoilerTV), Setrakian (David Bradely) and Fet (Kevin Durand) will race to recover the stolen Occido Lumen.

Meanwhile, Gus (Miguel Gomez) and Angel (Joaquín Cosio) hide a secret houseguest – is it Gus’ mother? – while avoiding a police sweep.

While the synopsis of “First Born” doesn’t state whether Eldritch Palmer (Johnathan Hyde) will make a better deal with Setrakian since he wants the formula of ‘the white,’ with the Lumen gone it seems like he will be more willing to make a deal with the Stoneheart CEO.

Furthermore, the promo teases an attack on Councilwoman Justine Feraldo’s (Samathan Mathis) headquarters. Looks like things are going to get a lot worse on “The Strain.”

Catch “The Strain” Season 3, episode 3 on Sunday, Sept. 11, at 10 p.m. EDT on FX.

The Strain “The Strain” Season 3, episode 3 will finally reveal some of Quinlan’s past. Photo: Michael Gibson/FX