Work pressure means I have to be (relatively) brief here, which is probably just as well since this is a very long book (not far shy of 1,000 pages in the edition I read) and my notes here might have been proportionately verbose.
The US military, hoping to develop a new superweapon, recovers from the remote wilds of South America a virus that (to simplify) turns people into near-immortal vampires. They “recruit” a dozen murderers from Death Row to be experimental subjects, plus one little orphan, Amy; I’m not sure why Amy is on their list.
Guess what? Things go wrong.
The vampires take over the world aside from a few enclaves where groups of plucky humans survive using artificial lights to keep the “smokes” at bay.
How long will the supplies of fuel and technology be able to keep the lights lit? Can the enclaves somehow contact each other, get together, drive back the monstrous hordes? Does Amy, herself near-immortal, hold the key to it all?
I’ve mentioned that this novel is a long one. It’s the first of three, the other two being shorter but not by all that much. In this context, the fact that what’s in effect the prologue to the main narrative lasts for more than 300 pages. And this setting-up section is genuinely gripping, despite occasional creaks from the plot.
The rest of the novel is set about a century after things went kerphutt for the human race. We follow the adventures of a group of survivors as they do their stuff amid a devastated landscape. I found myself fairly gripped by this narrative too, although in due course I became fed up not just of the increasingly intrusive bits of rickety plotting[*] but of being manipulated: several times the author deceives us into thinking that one or other favorite character has been gorily spifflicated, only to reveal a chapter or three later that, for reasons we could not have known, the character survived.
Cronin managed, despite all my grumbles, to keep the pages turning. A measure of his skill with prose is that I didn’t mind even those passages where, obviously drunk on the sound of his own voice, he let the words start running away with themselves, flooding across the page in a sort of self-indulgent excess of Thomas Wolfeian proportions. At the same time, though, I was very conscious of how derivative the novel is: Stephen King’s The Stand and Richard Matheson’s I Am Legend are the obvious precursors; I found minor elements also from Patrick Tilley’s Amtrak Wars sequence. Others have noted parallels with Cormac McCarthy’s The Road and Robert R. McCammon’s Swan Song, neither of which have I read. (Yes, I know: to my shame.)
Overall, then, while I quite enjoyed The Passage, I’m not hugely tempted to plunge immediately into the remaining volumes of the sequence. Perhaps one day . . .
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SPOILER WARNING
[*] The one that annoyed me the most came when Our Heroes have met up with an army battalion. Alicia, probably my favorite character up to this point, suddenly announces that her adoptive father enlisted her as a child into the army. There’s no question, then, but that she must become part of the battalion, sloughing her friendships with Our Heroes. Yet, in real life, either Alicia would have kept her mouth shut or the battalion commander would have detailed her for the duty of looking after her civilian comrades. There was absolutely no reason, beyond plotting convenience, for the split.
Noirish 
You can avoid the wrestling anthology, I’ll give this one a miss!