Bob Levinson is a father of seven children with a big, talkative and friendly nature. He has been married 33 years.
He is now retired from the FBI after more than 20 years as an agent; his family says that he worked as a private investigator for corporations on things like produce smuggling and that he helped news organizations like ABC and NBC.
But when Levinson's family said goodbye to him almost five months ago, as he departed on his first trip to Dubai, United Arab Emirates, it had no idea that would be the last time family members would hear or see Levinson.
Various reports suggest that he went to seek out information on cigarette smuggling for a client of his security firm, but it's not clear whether Levinson ever landed in his assumed destination of Dubai. He was last seen in Iran and his whereabouts are unknown.
"You're talking about a man who lived for his wife and children, and for him not to be around is uncomprehendable to us," his daughter Susan Levinson said. "It's scary. We don't know if he will ever come back. We don't know if we'll ever know what happened to him and that's our biggest fear."
Susan Levinson said she still calls his cell phone to hear his voice sometimes.
"It's very hard because I do live with my family," she said. "I'm constantly reminded of his absence. Everything around us was dad. So it, it's hard. Every place we go, dad has taken us to."
The family traced Levinson's flight to the Iranian resort island of Kish. From there the international mystery of his disappearance begins to look like something from a spy novel.
Now several questions have arisen. What was Levinson doing? Was he working for a corporation or a reporter at some network? Was he taken by the Iranians as a bargaining chip in the standoff with the United States?
"We know he entered in Iran," the State Department said. "We have repeatedly asked authorities for information about his whereabouts."
Adding to the mystery is Dawoud Salahuddin, an American who changed his name and left the United States after allegedly assassinating an Iranian diplomat in the 1980s.
Salahuddin, an American fugitive, said Levinson disappeared after an innocuous meeting with him in Iran.
Christine Levinson said that as she waits for her husband's return, she worries about his health.
"He has some medical problems too, and because he has diabetes and he has high blood pressure … and we are concerned because he is also 59 years old," she said.
She said the family has taken the incident one day at a time.
"Every morning we wake up hoping he'll be home that day, and of course, it hasn't happened," Christine Levinson said.
The children watch old home videos of him playing around when they were little, she added.
"They cry themselves to sleep at night," Christine Levinson said.
Christine Levinson said that her husband was not a spy and that she does not believe he was doing dangerous work.
"Bob could not be a spy," she said. "He's such an open person. He went there under his own name. And so for him to, for anybody to think that he could be doing something like that, people who know him know it's not possible."
She said that if her husband lived a secret double life, she would have known about it because he was at home often and owned his own business.
"He took a lot of trips out of town, but at the same time, they were for major corporations," she said. "I knew the people who were in these major corporations that he was talking to."
Levinson funded the trip himself, according to his wife. Salahuddin confirmed to Christine Levinson that her husband was talking with him about cigarette smuggling in the area.
"He has not seen Bob or heard anything about Bob," Christine Levinson said. "But he said that his friends say that is he's [in Iran]. I don't know any more than that."
Christine Levinson said she has been in touch with the Iranian government, and she even wrote a letter to its president. She has yet to receive a reply.
The couple's son Dan Levinson said he believes the U.S. government and his father's former FBI colleagues are doing everything they can to locate him.
"Some of the people working on this are not getting a lot of sleep," he said. "They're losing vacation time and they're sacrificing everything to bring him home for us."
Christine Levinson said she and her son plan to go to Iran if they don't get any answers in the near future.
"He is the most generous man in the whole entire world, generous with his time, his money, of himself, of his advice," said Susan Levinson. "To not have somebody like that around for our family is heartbreaking, and we're all heartbroken. And that will not mend until he comes home."