Ruta Gedmintas as Dutch Velders and Kevin Durand as Vasiliy Fet in “The Strain.” (Michael Gibson/FX)

FX’s gratifyingly gross horror drama “The Strain” returns for a second season Sunday night — and not a moment too soon, as summertime TV grapples with a serious case of the blahs.

Guillermo del Toro, Carlton Cuse and Chuck Hogan’s saga of New York falling prey to an epidemic of viral vampirism can’t really claim much in the way of originality or artistic breakthrough, but it does have the confidence and sense of purpose that defines good, pulpy genre fiction. It is scary without being particularly terrifying, with gore that is expertly attuned to Halloween-industry standards. You could call it predictable, but “The Strain’s” strongest selling point might be its reluctance to encourage broader thoughts about apocalypse, the way AMC’s “The Walking Dead” does with zombies. The fun here comes without that extra layer of philosophical fanaticism.

In that sense, “The Strain” is an enjoyable (and sufficiently sicko) episodic diversion. Sunday’s story picks up where things left off, after a rogue government epidemiologist, Ephram Goodweather (Corey Stoll), and an elderly vampire chaser, Abraham Setrakian (David Bradley), were able to briefly corner but not kill the beastly Master (Robert Maillet) who controls the city’s vampire breakout.

“The Strain’s” vampires are not the pretty, talkative kind; they transmit a worm parasite delivered via a fanged tentacle that pops out of their necks — a process splendidly rendered with a mix of CGI and good ol’-fashioned makeup.

Retreating to their outer-borough warehouse hidey-hole, Ephram, Abraham and a determined band of survivors have conflicting ideas about what their next move should be: Even though alcoholic Eph has fallen off the wagon as a result of all the chaos, he and his lab partner/lover Nora Martinez (Mia Maestro) get busy devising a new virus that will combat the vampire cells. Tough-guy rat exterminator Vasiliy Fet (Kevin Durand, the show’s standout) decides the thing to do is secure a fortress block-by-block — a sentiment shared by a tough-talking city councilwoman (Samantha Mathis) who implements a vampire-killing policy in her Staten Island district.

Abraham, meanwhile, pores over his leatherbound collection of European bloodsucker lore, seeking a solution that has eluded him since he was a young prisoner in a Nazi concentration camp and first encountered the Master. The mystery of Abraham’s advanced age (he’d have to be in his 90s for the math to work out, based on the flashbacks we’ve seen) is given a fairly intriguing explanation this time around.

“The Strain,” like any fast-moving thriller, depends on its ability to juggle several plot threads (including the schemes of a billionaire who bankrolls the Master and a brotherhood of vampire ninjas dedicated to stopping the Master) and bring them together in a way that doesn’t become too old-hat. The show doesn’t always succeed in this regard, particularly with the tedious seroconversion of Eph’s adolescent son, Zack (Max Charles) — not into a vampire but into yet one more of those troubled teens who can drag down just about any cable drama. Who has the time to watch Zack grow into a useful character like “The Walking Dead’s” Carl?

Anyhow, the boy is obsessed with finding his mother (Natalie Brown), despite Eph’s repeat assurances that she’s become a cold-hearted worm-vamp. Turns out, she’s been promoted by the Master and given a herd of blind kiddie vampires (a.k.a. “the Feelers”), that she commands to hunt down her son. I say let her have him.

The Strain (one hour) returns Sunday at 10 p.m. on FX.