Clocks -- there are at least five of them, none of them telling the right time -- dot the walls. And calendars too, out of date and unmarked; no birthdays, events or memories written into them, just left blank.

This is the home of Manee Chanviset, 77, and Samarn Charoensuk, 78, a Thai couple, whose children left them behind long ago. One, their youngest, Maleenu Charoensuk -- nicknamed "Lek" -- had been missing, feared dead, for years. Now they sit in their home, alone.

When their children left, times got hard. The parents were reduced to picking through garbage, scavenging to find things that they could sell, so they could eat.

Improbable rescue

Theirs would have been an untold misery, but for the Labour Rights Promotion Network (LPN), an NGO which found Lek, improbably, stranded on an Indonesian island. They took down information about his family and his hometown, and tracked down his parents.

They spoke for the first time in almost eight years, a call arranged by LPN, ears pressed against a borrowed mobile phone.

When we arrived at their home it's time to join them as they pick up their son from the airport. They don't have the money to go themselves so another NGO, Stella Maris Seafarer, is taking them. As we walk in, the organization has also brought the couple some provisions, the result of donations.

It's an extraordinary turn of events for the elderly couple.

Long-overdue reunion

She doesn't have much, but Lek's mother, Manee, buttons up her best, blue silk shirt. It hangs from her thin figure, but she looks so happy -- and nervous.

She called Lek's estranged sister for moral support as soon as they heard the government was bringing him back to Thailand, and she is part of the welcoming committee -- an ever-increasing number of family and relatives who have returned to witness his homecoming.

But his father won't go to the airport. He says he is not well and too weak, but it seems he is overwhelmed. He breaks down as we set off for the airport, his head in his hands. Tears of joy -- and perhaps disbelief -- that their son is finally coming home.

Manee has never even been to the airport before, but this trip is one she's longed for for years. The entire journey she speaks quietly, in a daze.

"I never thought this day would come," she says. "My heart is pounding. All I want is to see his face. All I want is to see his face"

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Reunited

When they spot him they cry, and she clings to him, her tiny frame trying to hold him in this moment for as long as she can.

"Let's go home... let's go home," she whispers. "Don't you go anywhere again." She takes a good look at him. He is much thinner, and he looks so much older.

Lek is in shock at first. He can barely speak but tells his mother, the woman he hasn't seen for eight years, that he didn't think he would ever make it back home.

He had disappeared without a trace, without warning. His parents assumed he'd taken a fishing job, like he'd done once before.

It's not difficult at all to see why poor young men risk their lives at sea, to try and earn some money to alleviate their extreme poverty.

His family's home is a rusty shack of carefully choreographed corrugated iron -- his parents must have built it years ago, before their strength left them.

Tricked, kidnapped

He tells us how he was tricked onto a boat, at the very beginning of his eight-year ordeal.

"I was drunk and they took me to the boat," he recalls. "I told them I wanted to leave but they didn't let me. They hit me and forced me to board. There were so many men."

They told him he could go for a three-month trial and that he was free to leave if he didn't like it. He didn't know then that he wouldn't see his home for almost a decade.

He says he was on the boat for about seven months before it landed at a port in Indonesia.

"Some of us got off to buy some drinks for fellow workers. The captain was so angry he beat us and stabbed me. He abandoned me on an Indonesian island. "

"There, I was stuck on land carrying rocks in exchange for food," he says, eyes downcast.

READ MORE: Thai PM vows to clamp down on slavery in fishing

Rescue

He was discovered by LPN only when Indonesian authorities began a clampdown on illegal fishing boats in their waters. Thousands of men from countries across Southeast Asia poured off the boats, telling tales of being trapped at sea. Others were already on islands like Lek's, abandoned with no paperwork.

Now he's home, he won't go back, he says. And his parents won't let him. They cling to him.

But Lek -- and hundreds of others like him -- is returning home to the same poverty and lack of prospects as they suffered before.

They may have just returned but have a long journey ahead; the struggle to settle back in and to find work to feed their families -- in the same conditions that led them, years ago, to being trafficked and forced to work as slaves.

How to help: Global hotlines to report suspected cases of human trafficking

CNN's Kocha Olarn contributed to this report.