As postal worker Sheryl Hancock is putting up the overnight mail, she notices that Mrs. Gunderson's nephew Paul is sending his aunt another postcard, and this one is from Rio de Janeiro. Mrs. Gunderson is a sweet little old lady who chats with the postal workers, brings them cookies, and shamelessly spoils her yappy shih tzu dog.
After Sheryl reads the message she tries to put it in Mrs. Gunderson's box. Noticing that the box is full, she starts to worry about whether or not Mrs. G is sick. By the end of her shift she has convinced herself that a drop by the customer's house to check on her would not take much time and it would put her mind at ease.
At the door a large handsome man with a mustache who fits the description of nephew Paul greets her. When the man realizes he is being mistaken for Paul, he pulls Sheryl inside the house and identifies himself as US Marshall Harry MacMillan. Harry is in hot pursuit of nephew "Paul", a fugitive who shot a law enforcement officer on his way to prison.
"Paul" and his so-called aunt are suspected of being involved in a smuggling ring that imports depleted uranium. Harry questions the reasons for Sheryl's visit to Mrs. G's and gradually learns that Sheryl has an almost photographic memory for what she reads, and she has read the entire series of postcards Paul has sent to his aunt. He has her reassigned to the Marshall's Office to assist in the investigation.
Sheryl is "almost engaged" to realtor Brian. The long question and answer period at Mrs. Gunderson's house had caused her to miss "an appointment" with him. (Can you stand the passion?) Soon, Sheryl's growing attraction to Harry makes it harder and harder for her to put that relationship in perspective.
Harry arranges it so he and Sheryl will have to work together to try and figure out the coded messages they think the postcards represent. Mrs. G. is hauled off to jail and Sheryl, rather than have the shih tzu go to an animal shelter, steps forward and offers to care for him. Much of the remainder of the book is devoted to the dog's antics during the
developing romance. In fact it seemed that every time the romance started to heat up, the dog was there having another adventure.
Why have I mentioned this dog so often? Simply because next to Harry and Sheryl, he is the most important factor in the book; it's a close call, some might even put him in first place.