THE parents of Shelley Pratt have told how their baby boy thinks his sister has been "taken by a monster".
Tony and Lisa Pratt have not seen their daughter since she disappeared five weeks ago after school.
Despite a large police search and the couple's own tireless efforts, the whereabouts of the 14-year-old is still unknown.
Now, as Christmas approaches, the family have told the Advertiser that they will not be celebrating the festive season until their daughter returns.
Mrs Pratt said: "It's been five weeks and I am trying to cope. I'm taking every day as it comes. I cry sometimes but I have to try and be strong for the younger children, I don't get to cry as much as I'd like.
"Her little brother is crying for her constantly, he just says 'I want my Shell, I want my Shell.' The youngest, Lou, doesn't really understand, he thinks she's on holiday, but the other day he asked if a monster still has Shelley."
The family home in Crowther Road, South Norwood, is covered in Christmas lights that were erected before the Westwood College student went missing on November 8.
Mr Pratt said: "The lights are up but we won't turn them on for good until she's home. I miss her so much. We need her back before Christmas. If she's not back by then, we won't celebrate properly. The younger kids will probably open their presents but I won't and her older brothers and sisters won't.
"It won't be right if she's not here."
The family have plastered the schoolgirl's face across the borough and beyond. Shelley, who was last seen on CCTV in High Street, Croydon, in the early hours of November 9, made no hints that she may be thinking of running away.
Her father said: "She seemed fine, she gave us no indication that she wanted to run. We still think someone has her."
Murder detectives are now searching for Shelley, although the case is not officially a murder investigation.
A Met spokesman said the team had been handed the case because they have more resources, expertise and are more used to making extensive inquiries.
The spokesman added that calls continue to come in from the public while the force is growing increasingly "worried" about the disappearance. Mrs Pratt said: "The morning she disappeared she seemed fine. She said goodbye like normal and met her cousin. She went to school like normal. Then after school she didn't come home. They've tracked her Oyster card till 9pm that night and we saw her on the CCTV.
"The pictures show her walking away. At one point she looked at the camera and smiled. We don't know why she was there at that time, we don't know what she was thinking.
"The police have been brilliant, we can't fault them, they've been helping as much as they can and keeping us in touch with everything going on. But we still haven't heard from Shelley."
Mr Pratt continued: "She's just a typical teenager. She sits in her room and closes the door and listens to music. She doesn't talk to us about boys or anything like that but as far as I know she didn't have a boyfriend.
"Now with the icy weather I can't go out on my bike as much to look for her.
"Before I was out for six or seven hours a night searching for her all over London, but with the ice I almost fell off my bike the other day, so we're going out in the car more often now.
"We're going out as much as we can and just hoping we see her face. I have friends all over London that are putting their pictures in their cars. Everyone in the area has been helpful and put the missing posters in their cars.
"I'm just so tired, we miss her so much. We need her back. Someone's got her and we want her back." Shelley's elder sister has told the Advertiser how much she misses her sibling. Tiffany Pratt, 17, has said she cannot stop thinking about her sister, who disappeared more than five weeks ago on November 8 after school. She said: "It won't stop bugging me, I really miss her, it's all I've been thinking about. All her friends are missing her, they had an assembly at her school the other day for her. "I used to go to that school and apparently one of the teachers is so upset about it that she's just crying all the time. Everyone misses Shelley." The 14-year-old has not been on her Facebook profile or had any contact with her family since her disappearance, and as Christmas approaches they have vowed not to celebrate without her. Tiffany said: "I just want her back for Christmas, it won't be Christmas without the whole family here. I definitely won't open my presents if she's not home, and my older brothers said they wouldn't either. "My boyfriend was meant to come to our house on Christmas Day but he's told me he won't if she's not found because it would feel like he's taking her place. "We always got along pretty well although we'd fight sometimes like sisters do. She never told me she wanted to run away or anything, I don't think she has, we all think she's been taken by someone. None of us are finding this easy. We need Shellz back.""
Anyone with information should call police 020 8721 4906.