'Do the right thing:' Lori Vallow's son begs her to reveal the location of his missing siblings

For the first time, Lori Vallow's son addresses her publicly as he tells her to "do the right thing."

His mother and her new husband, Chad Daybell, became close when she lived in Arizona. She then moved to Idaho to eventually marry Daybell.

The couple is now on the run, and her son, Colby Ryan, says enough is enough.

"Mom, I want to talk to you like I'm sitting across the room from you," Ryan said.

He can't call her, he can't see her.

Ryan says he's heartbroken and confused, so he went to YouTube to tell his mother.

"You have the power to end this," Ryan said.

His siblings, 17-year-old Tylee Ryan and seven-year-old Joshua Vallow, haven't been seen since September in Rexburg, Idaho.

Joshua Vallow, 7, and Tylee Ryan, 17, are being sought by police in Rexberg, Idaho. (Photo credit: Rexberg Police Department)

Authorities say Vallow and Daybell won't cooperate. The FBI is now a big player in the investigation.

RELATED: 2 missing kids, parents wanted: What the FBI, several law enforcement agencies are investigating

"Even if you just show them on FaceTime. Just show them on FaceTime to the police, it would be a lot better. I don't know what else I can tell you to do than just to know this is the right thing to do," Ryan said.

Relatives of Vallow all say she began to change when she joined a religious group believed to be extreme.

Court documents FOX 10 uncovered say Vallow claimed to be a God preparing for the second coming of Christ. And allegedly said she had visions to help gather those chose to live after the "Great War."

She is someone Ryan doesn't recognize.

"We had a life and it seems like that life never existed at this point," Ryan said.

RELATED: Interactive timeline of the disappearance

Multiple agencies including the FBI just investigated the home of Daybell in Idaho. Serving search warrants connected to his missing stepchildren and the suspicious death of his former wife, Tammy.

But still, there's no trace of the children or their parents.

"I'm your son. I would never want anything to happen to you. And I would never want anything to happen to Tylee or JJ, ever," Ryan said.

Police say Vallow and Daybell never reported the children missing.

If you have any information on Tylee or JJ, please call 1-800-THE-LOST. 

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