Sixteen-year-old Karlie Gusé vanished from the rural Mono County California home she shared with her father, Zac, and stepmother, Melissa, in the early morning hours of October 13, 2018.

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Melissa, says she had stayed up with Karlie most of the night - at the teenager’s request - after Karlie, who she claims was acting “very strange,” admitted to smoking marijuana

WATCH Stepmom Of Missing Teen Claims She Was Acting ‘Very Strange’ In The Hours Before She Vanished

“I had spent the whole night with her in her room, and when I woke up, she wasn’t next to me anymore,” says Melissa.

Why does Melissa say she “instantly panicked,” upon realizing Karlie wasn’t there?

Part one of this two-part Dr. Phil airs Monday. Check here to find out where you can watch.

If you have any information about the disappearance of Karlie Gusé, please call the Mono County Sheriff at 760-932-7549. Choose option #7.

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Dad And Stepmom Of Missing Teen Karlie Gusé Explain Why They Didn’t Share A Recording Of Their Daughter’s Last Night At Home With ‘Dr. Phil’ Producers