The family of missing County Down woman Lisa Dorrian have renewed their plea for help to find her body on the 12th anniversary of her disappearance.
The 25-year-old went missing after attending a party at a caravan site in Ballyhalbert on 28 February 2005.
Police believe she was murdered but have yet to find her body.
Lisa's father and sisters have recorded a video message specifically addressed "to the person who was with Lisa at the moment she died".
In her plea, Joanne Dorrian says: "Think about what happened when Lisa died, how you panicked and made a decision that would change your life and our lives forever."
She also spoke of the recent deaths of her mother and grandmother, and how distressing it was that they both went to their graves without knowing what had happened to Lisa.
Lisa's mother, Pat Dorrian, died in December 2015 and according to her family she "never ever got over losing Lisa" and "couldn't even function on a daily basis".
"The thought of her daughter out there with no grave tortured her, as it must do you," Joanne Dorrian said in her appeal.
She added that their grandmother, who died two weeks ago, spoke of Lisa on her deathbed.
"One of the last things she said to me as she was leaving this earth was that Lisa was at the end of her bed and was waiting with her," Joanne said.
"Our nanny and mum now have the answers we are trying to find. But you can help us find Lisa in this life, not the next."
John Dorrian said: "My daughter Lisa deserves to be found and laid to rest with her mum."
Addressing the person he believes was the last to see Lisa alive, he added: "It's never too late to tell us. A place is all we need.
"Please help yourself by easing your conscience. Tell us where Lisa is."
In their 12-year investigation, the Police Service of Northern Ireland have carried out 275 searches and taken statements from 571 people.
They made eight arrests on suspicion of Lisa's murder, but no-one has ever been charged with the killing.
During the early part of last year, they spent weeks searching land outside Comber, but did not find human remains.
The officer leading the inquiry, Det Ch Insp Justyn Galloway, said the victim's family and friends had suffered "intolerable grief".
"They cannot even begin to move on with their lives until her body is found," he said.
"Sadly Lisa's mother passed away last year without getting the answers she so badly wanted, but the nightmare still goes on for Lisa's father and three sisters"
He added that the murder inquiry "remains a live police investigation" and appealed for information.
The Dorrian family's appeal has been posted on their campaign website and across the PSNI's social media accounts.