Almost a decade has passed, but Thang still remembers every detail of the horrific event and the 30,000 kilometers he traversed looking for her.

In 2007 Luong, his third daughter, 16, asked him to get a cell phone to help with her studies. Tragedy struck when the innocent girl fell prey to sugary text messages from a stranger, and agreed to hang out and was tricked and sold in Guangxi, China.

Thang’s family searched far and wide, going through 11 northern provinces with a fine-tooth comb. He travelled to every place she could have possibly gone, looked in every Internet cafe, bus station, massage and karaoke parlor, but in vain. The last vestige of hope disappeared when the police said they could not find her.

Thang at present. Photo by VnExpress/Hien Trinh

It was then that he began to suspect his daughter had been trafficked to China. Someone pointed him to a man in Phu Tho Province who had tracked down his missing child, and Thang met and sought his advice.

He then began his journey with nothing but love for his child to guide him.

In November 2007 Thang took a train to Pingxiang, Guangxi. Alone in the strange city, seeing the crush of people at the local bus station and not knowing a single word of Chinese, he shed tears of frustration.

"How can I find my child in this huge crowd?" Thang remembers thinking in utter despair.

Luckily for him, a Good Samaritan appeared. Huu, a man who could speak Vietnamese, volunteered to help him. He took Thang to a police station, and showed him places where Vietnamese lived.

"I did not know Chinese, so he also wrote down some sentences of conversation so that I would not get lost," he says about the kind man.

Thang went to China a second time later, this time visiting some towns in Guangxi Province. A local woman was his benefactor this time, helping him travel to Nanning city and taking him to the Vietnamese consulate to report. After a few days of searching in vain his money ran out, forcing him to return home.

Challenge after challenge

A complaint Thang sent to Chinese authorities asking them
to look for his child. Photo by VnExpress/Hien Trinh

After the two fruitless attempts, Thang decided to prepare better since the next journey could last years.

He enrolled for a Chinese course in Hanoi. Though many years have passed, his Chinese teacher still remembers his diligence.

"He was the first person to arrive and the last person to leave the class. He used to stay after class to ask me the way to pronounce and write some place names in Chinese," Tran Thanh Hoa recalls.

At first Hoa was surprised, but she was so emotional after knowing his story.

"Sometimes I would not see him in class for a while. He would return saying he went to China to look for his child."

Thang then sold a piece of land to get some money and set off on another trip to Guangxi. This time he carried thousands of leaflets announcing a reward of VND50 million ($2,146) for anyone who could provide information about his daughter, but again he had no luck.

On subsequent trips he began to visit brothels to seek information since he guessed his daughter might have been sold to one of them. From Guangxi, he travelled to Yunnan Province and then Guangdong Province.

"The total distance I travelled was around 30,000 kilometers. Sometimes in just one day I travelled thousands of kilometers."

He never contemplated giving up, tormented as he was by constant memories of his child. "She was still young, and being sold into prostitution would be hell."

Thang’s trips were often dangerous, some even a threat to his life. Once when he was going through a village in Yunnan, he was surrounded by a group of armed people who thought he was a thief. But after hearing his story, they let him go.

Thang usually chose taxis driven by women. "If I got a male driver with evil intentions, I could have lost all the money and my life, not to mention not saving my child."

Magical reunion

A map of Guangxi Province in China Thang used to search for his daughter.
Photo by VnExpress/Hien Trinh

A year had passed when he returned from his 15th trip to China and there was the first glimmer of hope.

In late 2008 one of Thang’s other daughters received a message from her missing sister with the name of the town she was in. She was indeed in China.

When her guards had been distracted, she managed to sneak out and send a short message home.

Thang dropped everything and hurriedly left for China.

This time he called Huu, the kind Chinese man, and asked for help. Finding a brothel in the town she had mentioned, the two men entered the place pretending to be customers and asked for Vietnamese women. A young girl came out.

It was his daughter!

"My child!" Thang cried at the intensely emotional moment when he saw his daughter again after a whole year.

His heart was pounding, his legs were trembling, but he had to hold back his tears and pretend to leave.

The girl almost burst into tears on seeing her father after a year of despair at the brothel. But she too had to fake calmness to safeguard all of them.

"If we did not calm down, we could have died there."

They walked out and told the police. The wait felt like forever to Thang and he was also worried the pimps would find out and again spirit his child away.

But the police arrived, closed down the brothel and rescued 10 Vietnamese girls.

Before the 2009 New Year the Chinese police returned Thang’s daughter to the Vietnamese Border Defence Force more than a year after she had been trafficked to China.

It is more than 10 years since it happened, but an officer still clearly remembers the case of the man who tracked down his trafficked daughter himself in a foreign country and reported to the police.

Things have been much happier since for the Thang family.

His daughter resumed her studies.

She now has a happy family with two children and an understanding husband.

"Many people ask me how I was so persistent.

"Because I am a father.

"I think any father in that situation would have done the same."

 *Names have been changed to protect privacy.