Becoming very suspicious
Sara became much more cautious about what Mark told her after that. The money going missing would turn out to be the beginning of a series of unusual incidents and discoveries that began to make Sara suspicious and concerned about what Mark was doing.
Mark often traveled to the same place
Sara began to notice that some of Mark’s trip stories didn’t make sense. He always said he flew all over the nation and nearly never went to the same spot again. When Sara “accidentally” inspected Mark’s flight history, she saw he frequented one airport in particular. Why would he lie about this?