Ellen, I find your question very intriguing.  Yes, I have read Derailed, so I offer some what may hopefully be helpful comments.  Firstly, let me warn the reader here who isn't Ellen (and, if it is...

HI ELLEN!)

and who might like not to know anything about the book, Derailed, because you're planning on reading it.

A FEW COMMENTS ABOUT "DERAILED"

I enjoyed the book quite a bit.  It's a quick read and, notwithstanding some graphically violent and sexual moments, the author speckles the narrative with wit and a sharp astuteness, and allows you to feel like he's telling you what happened over some drinks or coffee.  Definitely a personable storytelling approach.  The downside of this otherwise positive trait of the book is that it depends a great deal on this narrative, which could be translated into a voiceover.  But the problem there is that there is a great deal of analysis and intellectualizing that would most likely not hold up in a fast-paced thriller.  Although jeopardy abounds in this tome, the storyline minus what would be the voiceover could appear too thin and overly direct for it to work as a thriller on the screen.

Yes, there are some twists, but, because audiences today have been inundated with these so-called twists, they have come to expect them, their "twist radar" being fully turned on and tracking.  The difficulty with Derailed as a screenplay and film contender is that, the way the story is set up, we know a twist is in the making and even guess what it is.  So by the time the protagonist makes The Big Discovery, we're waaaay ahead of him.

The author uses too many happenstances.  Maybe one we'll accept.  We'll stretch our belief taffy a little for the writer.  He's been good to us, moved the chapters along nicely, left mini-cliffhangers at the end of each one, didn't use too many difficult words to understand.  But the second one, the amazing Just Happened To Happen At The Perfect Moment moment, which happens to happen at the very place where our protagonist happens to be, coupled with the apparent invincibility of the protagonist while more than a hundred others around him don't seem to have that same invincibility... is too much.  Actually, this moment I speak of is not set up well and comes across as a deus ex machina (literal meaning:  God from a machine), which, in this case, is an unadulterated unbelievable contrivance that ruins all the preceding and otherwise generally captivating material.

I'm not saying that a producer couldn't have Derailed adapted for the screen because of its many merits -- especially the author's plotting and structure (he makes us wait until the very end to explain the introduction, a very satisfying and clever explanation, indeed) the main one being that we follow this rather unobtrusive, plain man who has an affair with an intoxicating woman, which puts his life in shambles as he crosses into a world of violence, debauchery, where he must for all intensive purposes live a double life, one that includes murder.  (Sort of sounds like something you might find on the DVD cover, huh?).  But there would need to be more than a modicum of rewriting to deepen the story and not lose us along the way as we jump off our own Credibility Train.  

I hope that helps you, Ellen, and anybody else who has read the book or is thinking of reading the book or is thinking that he or she wishes she had never read this e-mail because he or she was just about to read the book but now, because I've ruined it by writing about it... won't.

DcH