Especially if you suspend disbelief and don't dwell too deeply or too thoroughly about the exact nature of the film's menace.
In short order, we get insert shots of the book's interior, and our eyes register pages devoted to such topics as "the Roanoke Colony" and "dark matter."
There's a power outage and everyone sitting inside Paul's theater vanishes, leaving their clothes and popcorn behind. Paul survives, but he seems to be the last man standing.
It's as though the vanished people have been taken, yet their mobile, malevolent shadows remain here on Earth as sentinels. Many shots also feature creeping darkness spilling over walls and bridges like an unending supply of black paint, descending irrevocably upon terrorized, doomed characters.
The idea of creeping blackness devouring matter and light is not new. It was vetted brilliantly (and with hair-raising horror...) some thirty years ago in Sapphire and Steel's second serial, set at an abandoned train station. And, *ahem*, I myself used dark matter and the Roanoke disappearance as narrative connections in the second season of my web series, The House Between (2007 - 2009), particularly in the episodes "Distressed" and "Ruined."
Finally, the character names Luke, Paul and James specifically recall Scripture, so I felt these monikers were also a sub-textual hint about the nature of the "event" as well.
None of this information qualifies as a spoiler, however, because it would be just as easy to read the mystery another way; with another point of view. Someone could have an entirely different theory from mine, and still make it work.
The creeping darkness makes for a splendid visual menace in Vanishing on 7th Street, and Anderson handles it ably. The problem, however, is that -- as one character states -- "the math doesn't add up." If the survivors go into the darkness without a light, they vanish. Fine. Well, how much light are we talking about here, and what kind of light?
Instead, setting a fire would be a guaranteed way to keep the darkness at bay for a good long time, I would think.
In fostering a feeling of spiritual catastrophe, of existential angst, of faith or lack thereof, it is not necessary for the threat to make conventional, scientific sense, one might argue. God Moves in Mysterious Ways and We Do Not Understand Them. That's sort of the point, I submit, and though I generally hate that idea because I think it's a dramatic cheat (see: Battlestar Galactica's finale...), in short form like a 90 minute movie I find it far less objectionable than as the solution to a multi-season mystery (also see: The Lost finale).
For the most part, this is a mood movie about four people who end up in a bar together after the rest of the world has disappeared, and wonder what the hell happened. It's a perfect Twilight Zone premise, and the execution is good even if I don't quite buy all those moments in which the shadows creep up and almost get a protagonist, then a character crosses into the light and it retracts. Somehow it feels too easy; to simple.