Dean Koontz's One Door Away from Heaven was one of those audio books that I didn't recognize by title but it wasn't too far into the first CD before I realized I'd listened to it before. That's OK - it was worth another listen.
Koontz is able to take a nugget of scientific fact (in this case, the field of utilitarian medical or bio ethics), shine a rather creepy light on it, surround it with real characters (real in the sense that they're flawed), and turn it all into a great tale. My first Koontz book was Mr. Murder (thanks Heather) and since then I must've listened to dozens of his books.
In ODAfH, a 9-year-old crippled yet precocious girl (Leilani) fights a mental battle of wits and survival with her junkie mother and bio-ethicist stepfather. She charms her neighbors, a recently paroled young woman (Mickey) and her eccentric aunt. When Leilani and family disappear overnight, Mickey fears the worst and gives chase. Coming from the other direction on a completely different mission is a young boy and his dog on the run from assassins. When their paths cross, things get really weird. I won't even mention the gunslinging Vegas showgirls.
If you haven't tried Koontz before, give this one a shot.