Never Tell a Lie by Hallie Ephron
Ivy and David Rose, happily married high school sweethearts, are trying to clear out the junk the previous owner left in their glorious Victorian in Brush Hills, Mass., before the birth of their first child. They have a huge garage sale and among the bargain hunters shows up Melinda White, a high school classmate who's also pregnant. At first neither Ivy or David remember her but they vague memories come back. But Melinda seems almost desperate to create a connection with Ivy who gets more and more uncomfortable with her. When David offers to show Melinda the inside of their house Ivy is relieved and thinks no more about it.
Then when the police show up to report that Melinda has disappeared and no one can remember seeing her leave the sale, the evidence suggests the couple murdered her. Evidence keeps mounting against them until Ivy is almost convinced that her husband may have actually killed Melinda. We start seeing the cracks develop in their perfect marriage as Ivy alone must figure out what is real and not. Plus the actual reality of the story is much more devious than what first appears to be the mystery.
This book was impossible to put down, I read it in one day as I just had to know how this ended up. The ending really didn't surprise me as I suspected the twist that came but still it was well done. There are many ethical issues that are brought up and not really resolved but then I think that is how life is too. While the book ends - it leaves many unanswered questions - most of all will their marriage survive the truth.
Good book for vacation or business trip.