[THIS REVIEW CONTAINS SPOILERS FOR PAST SEASONS OF “THE STRAIN.”]  I love “The Strain.”  It’s weird, it’s wacky, it’s usually creepy, and the screenwriters seem to want to throw in everything but the kitchen sink in order to please horror fans.  It’s also the most ambitious horror show on television — it endeavors to depict nothing short of an entire vampire apocalypse, from its inception back in Season 1 to what appears to be a complete victory by the monsters at the start of its fourth (and apparently final) season.  Only the outstanding “Fear the Walking Dead” has attempted something like that.  And although “Fear” is the better show, it can’t match “The Strain’s” epic storytelling goals and its level of detail.

The writers’ energetic efforts almost always pay off.  Part of “The Strain’s” appeal is that you never know how far they’ll go.  And they do push the envelope so creatively that they sometimes hit upon ideas and story points that are grotesque and darkly creative.  I’m still enjoying this show even after I predicted back in Season 1 that the plot-driving creatures themselves would grow boring after our repeated exposure to them.  (I’m happy to be proven wrong.)

Regrettably, the Season 4 premiere suggests that the writers are now reaching too far, too fast.  It continued the show’s pattern of brave creative choices, but it was sloppy.  There were enormous changes in story and setting with insufficient exposition.  We jump nine months forward from the close of last season, when a nuclear explosion devastates New York, and our heroes are scattered.  We’re offered little information about how our protagonists arrived at their respective new junctures, and that is forgivable.  (It’s a convention of serialized storytelling like this that things can be explained in subsequent episodes.)  But the enormous changes in the overall milieu left me a little confused.

Following the nuclear conquest of New York last season, why would Philadelphia and other cities also be ruled by the vampires?  I understand that the nuclear winter is to blame for this, because the bad guys can move about by day.  But would a single bomb cause a sufficient nuclear winter to affect the entire Eastern Seaboard?  (Yes, I am aware that I am illustrating my ignorance of this subject.)

Or … is it the entire continent that’s affected, or the entire northern hemisphere?  Have other cities been bombed or not?  Why are the vampires seeking out more nuclear devices?  (We are given confusing information about these things through new story elements and dialogue.)  Furthermore, why is Vasiliy Fet (the likable Kevin Durand) trying get his hands on a nuke on behalf of the human resistance?  Is he planning on nuking an entire city, with both vampires and their human slaves?  If he neutralizes “The Master” in the remains of New York City, will it be worth it?

These are important plot and story elements that left me scratching my head.  What’s more, the season opener was further marred by some pretty spotty scripting and direction.  (The action sequence at the end was poorly done.)

The episode was still fun enough.  I’d rate it a 7 out of 10.  I’m just surprised that an episode that seems so hastily developed served as the season’s opener.