Millie and John
In this sequel to To Kill a Cat, Millie and John Austin's beloved cousin, Mark Austin, had disappeared. He had left the country without telling them or anyone else that he was leaving or where he was going. With the help of two clues provided by Mark's maid, Maria, Millie and John were able to determine that Mark was probably in San Miguel, Mexico. They decided to go there and look for him. There, they learned that he had been murdered and buried in an unmarked grave in a remote area of the state of Guanajuato.
John was able to gain access to Mark's two bank accounts. One was in San Miguel; the other was a Swiss account. With this extra money to spend, Millie and John decided to extend their stay in Mexico and do some sightseeing. They had many memorable adventures in Mexico, which included the celebration of their thirty-second wedding anniversary and an unexpected tragedy.