Determined to get to the bottom of this mystery, Lisa decided to hire a private investigator to track down Celeste. She gathered the copies of the letters and made an appointment with a well-known investigator in town. When they met, Lisa handed over the letters, explaining the situation as best she could. The investigator, a middle-aged man with graying hair, nodded thoughtfully as he took notes. "I’ll do my best to find her," he promised, his tone serious. As days turned into weeks, Lisa’s anticipation grew.