In 1989, Annie Tahan disappeared without a trace. She left behind a newborn daughter and her boyfriend, Chief Petty Officer Michael Paalan, who told police that she had walked out on him. Four years after she disappeared, and with little to go on, authorities in Charleston, S.C. asked NCIS for help. "The mere fact that Michael Paalan was an active duty sailor at the time, we had an obligation to seek out the truth," said retired NCIS Special Agent Pete Hughes. Did Paalan have something to do with Tahan's disappearance? It would take years of challenging investigative work, multi-agency cooperation, surveillance and a sting operation to get answers. Moreover, they were investigating one of their own, making the case even tougher.