The Vile, Sinister, and Most Utterly Diabolical Account of Latrina Emerson

What would Latrina Emerson, unassuming librarian and church organist, have in common with an agnostic physicist and a bunch of occultists over 2000 miles away? Absolutely nothing if she could help it. Some not-so-benevolent "Forces of Light", alas, won't let her help it. She's part of their plan save their credibility after some recent embarrassments (Y2K failing to end the world on prophetic schedule, increasing distrust of authority, etc) and shut up those smart alecks in the Forces of Darkness.
But the Forces of Darkness have never followed the Light's rules-like the ones that say they have to be totally evil or always lose in the end-and they're not about to start now. A faction of Hell, in fact, has decided that despite religious and philosophical differences, Latrina is too decent a person to be martyred "for the greater good". Warning her, however, gets a bit tricky.
And the real wild card may be Latrina herself, who may not be as "manageable" as the Powers-That-Only-Think-They-Be would like.