Once the battle begins, however, the tension dissipates.  "But as long as the threat hangs over the characters, as long as you suspect that something awful is going to happen, you're on the edge of your seat. When violence actually occurs, there's nothing more to fear."

Which is why Gerritsen keeps the violence "at bay for as long as possible, while simultaneously maintaining a continual sense of threat."

Gerritsen's technique is hard won. She begins her writing day with coffee and does all her first drafts with pen and paper. " I've tried composing on computer," she says, "and it never works."

Her writing sessions, she explains, are usually accompanied by a lot of sighing, moaning, and sounds of pain.  "It's hard for me, and it never gets easier."

But that hard work shows up on the page. One example is her 1995 bestseller, Vanish. "There's a scene," Gerritsen says, "where two young women are hidden on the roof and can hear the sounds of murder going on inside the house. Only when things go silent do they dare creep back into the house, and find their housemates slaughtered.  They know they need money and warm clothing to make their escape, so they frantically gather those necessities before fleeing.  During which you the reader are thinking get out, get out NOW!  Nothing violent happens to them in that chapter.  But because you know the killers could come back any minute -- indeed, the killers could already be watching for them to step out of the house -- you expect the worst."
Gerritsen explains further, "It's the sort of scene, if it were a movie, where you'd hear the nervous tremolo of a violin in the soundtrack.  I guess that's how I'd best describe it -- the scene with something's about to happen theme music!"

It's that kind of music that keeps readers turning the pages in a Gerritsen novel.

James Scott Bell is the author of Try Dying (Center Street), first in the Ty Buchanan thriller series, and Write Great Fiction: Plot & Structure (Writers Digest Books).