Let Sleeping Dogs Lie is a short novel that I think you will enjoy. It’s about a woman in her early 50′s named Mara Byrne. She’s a 
writer and has been happily married to the same man for almost thirty years.
Her husband, Thomas, dies very unexpectedly and she is devastated.
In the process of cleaning out some of his stuff to donate to a charity, she discovers a set of keys. With the help of her neighbor, she finds out they are safe deposit keys.
In the safe deposit box she finds a letter from another woman.
Mara becomes obsessed with finding out the identity of the other woman and whether or not her husband had an affair.
With the help of an attractive private investigator, Alex Strange, she searches for answers to her questions so she can get on with her life.
I don’t want to give you too much, but I will say this, Mara and Alex may find themselves working together again in my next novel.