Samantha Fayet and her baby daughter Ruby are among the hundreds of Britons still missing in Thailand after the Asian tsunami.
Their family has faced an anxious wait for news on their fate, with no contact from them since Boxing Day. They told the BBC News website how they have been coping.
Now Samantha's sister, Nathalie Archer, has returned to Thailand to resume searching for the pair. She has told the BBC of her exhaustion, her frustration - and her conviction that her sister is still alive.
"I don't believe they're dead so I have to continue," Nathalie said after a long day searching in the mountains above the Khao Lak beach in southern Thailand where Samantha, 33, and her six-month-old daughter Ruby were last seen.
Many hotels were destroyed at Khao Lak beach
"People might think I'm completely crazy, but I haven't had the feeling that she died and I'll keep searching as long as I can."
Nathalie, 35, first flew to Thailand in the immediate aftermath of the devastating wave that hit the country on 26 December.
At that time she spent days looking through hospitals and makeshift morgues for some trace of her sister and niece.
Nathalie estimated that she had seen as many as 3,000 corpses during those few days.
She was forced to stop searching when she realised her brother-in-law Patrice, who survived the disaster, was seriously injured and severely traumatised, and needed her to return him home to Paris.
She flew back to Phuket on 10 January, determined to follow up any scrap of information that could help locate Samantha and Ruby.
Nathalie made two appearances on Thai television to ask for help. The response was overwhelming, she said, although not all calls had been helpful.
"Most people that I could ring back denied having rung in the first place," she said. "Others had called to say 'happy new year' and one man said he loved me."
With the leads that did prove productive, Nathalie was able to focus her efforts on a mountain area on the fringe of Khao Lak's massive national park, above where her sister had been staying.
She thinks Samantha may be hiding, scared and almost certainly injured, somewhere in the hills.
Samantha Fayet has not been seen since Boxing day
"I walked for six kilometres through the national park today and it is absolutely exhausting in this heat. I'm not particularly fit either and it's very time-consuming," she said.
"On the first day I was very tired and I felt like I was banging my head into a wall. One day in all this heat with all this strain feels like 10 days."
Two Thai national parks guides are travelling with her. The Foreign Office had provided her with a car and a local driver.
Most roads have been cleared, but recovery teams with cranes are still looking for bodies in a nearby swamp.
Nathalie's search remains an agonisingly slow process, combing the area and hearing conflicting stories from survivors.
"One person said there was a woman in a refugee camp with a baby, another saw a woman wandering along the street looking confused, another said she had been taken in by a local woman.
Elephants have been used to clear debris in the hills
"Now if one person was taken in by a Thai woman, then maybe there are more. There are so many maybes and unknowns and that's why I'm carrying on."
But while she remains positive that her loved ones will be found, she knows there may be a more grim discovery awaiting her.
"If I do find my sister [alive], she might not have the baby. There are a million traumas we may have to go through at some point, but I need all my strength now for searching."
And with three children of her own, she knows she cannot search forever. She is due to leave Thailand on 17 January, but at this point she would rather not think about the prospect of having to return with no news.
"The embassy says lists [of those who have made contact] are changing daily, new names are appearing. Every day brings new news, so I'm still hoping."