Nightworld: A Repairman Jack/ Adversary Cycle Novel by F. Paul Wilson (2012): If you've seen the mostly godawful Michael Mann movie The Keep, then you've met the Anti-Christ of F. Paul Wilson's apocalyptic Repairman Jack/ Adversary Cycle. The novel was much better. But that was him, rassling Scott Glenn after escaping from centuries of imprisonment thanks to those damn Nazis. Scott Glenn played Glaiken, Rasalom's equally old nemesis.
Well, here we are now, after more than 30 years, with the end of the whole shebang. Nightworld is a major revision of an earlier novel of the same name, changed to increase Repairman Jack's role in the apocalypse, among other things.
The Earth's days get impossibly shorter, day by day. In a week or so, the sun will set for the last time. Massive pits begin opening up across the planet. When night falls, giant carnivorous insects pour from the pits. Worse, larger things soon follow. Volcanoes erupt. Earthquakes shake the planet. And it's all just a preview of life on Earth once the Otherness fully arrives and Rasalom emerges from his cocoon to preside over the fallen Earth.
And so a ragtag group of heroes must find and reassemble a thingie that might allow them to defeat Rasalom and drive away the Otherness. Rasalom draws power from fear and despair in his cocoon below Central Park. And his former followers discover that he never intended them to share in the power on the day after Doomsday.
Nightworld mostly satisfies, though the massive body count of the previous installment leaves sympathetic characters a bit light on the ground, and the gathering of items (or 'plot coupons') is a fantasy trope that, much-used, is also pretty much standard at this point in the genre. Still, things remain tense and compulsively readable right to the end. Recommended.