But authorities were confused. Her cell phone signal was coming from Sarpy County, Neb., not Omaha. Nevertheless, they sent police to the Mandalay and found nothing.
If they had been lost in almost any other state Hornickel and Wamsley might have been found. But Nebraska is one of just nine states that does not have the most up-to-date 911 GPS tracking system for cell phones, so operators could not pinpoint their location.
At 1:05 a.m., Wamsley called 911. He said he and Hornickel had left the truck, but he still insisted they were near the Mandalay apartments. Dispatcher Patty Viberg told them a police unit had been sent and could not find them.
"They need to come further south. Further south, open the gates," Wamsley responded. There are no gates in the area, but still another police unit was sent to the area around the apartment complex.
By this time, several operators in three counties were talking to each other trying to figure out where the couple might actually be. They suspected drugs were involved.
At 1:45 a.m., Wamsley called again. Knowing how cold it was outside, Viberg urged him to return to his vehicle. He said it was "rolled over on its top," and Viberg feared it could be leaking gasoline. But the truck was actually upright, just off the road.
Wamsley also said they had encountered people, but he didn't think they spoke English. "We've tried, we've asked for help, we've begged," he said.
Around 2 a.m., they called again to say they had stumbled on a small, unheated shack. Worried about their safety in the sub-zero temperatures, Viberg asked him to stay there. She also asked Wamsley if he had done any drugs that night. He said no.
At 3 a.m., Wamsley called back and said he was going to walk some more, and left the shelter of the shack.
The last call came at 4:20 a.m. The couple had been out in below-freezing temperatures now at least four hours. Wamsley's last call was short, less than two minutes.
"Hey, this is Mike Wamsley," he told Viberg. "I have just escaped. Please come get me."
Hornickel's mother, Twilla, said she had no idea about Wamsley's alleged drug use: "She always said that Mike didn't drink and Mike didn't use drugs," Twilla said.
Twilla Hornickel says she can't imagine what could have happened. She saw her daughter in the early part of the evening on New Year's Eve, and says she didn't notice anything strange.
"They had normal sleep patterns, they played games with the kids," she said.
But Capt. Rolly Yost of Sarpy County, who led the investigation into the couple's disappearance, suspects something went wrong later that night.
"We know where they were. We know parties they were at. We know there were drugs at those party locations," he told "Primetime." He said Hornickel might have tried meth for the very first time at one of those parties.
He also has a theory about the "people" that Wamsley mentioned in his phone call to 911.
"It's quite possible he sees the cattle, hears the breathing of the cattle, and thinks these are people. These 'people' aren't helping him. He's calling out for help and they are not responding," Yost said, adding that his theory was speculation.
Twilla Hornickel doesn't blame Wamsley for her daughter's death. "He respected her. He was always kind to her. I don't know what happened," she said.
Meanwhile, investigators trying to find the source of the methamphetamine have arrested a mother and son who live in Kearny, Neb., and charged them with possession of methamphetamine.
Hornickel and Wamsley attended a party at the house of Judith Morel, 48, and Mica Morel, 19, on New Year's Eve.
Authorities have not said whether they believe the Morels supplied Wamsley and Hornickel with methamphetamine. The Morels refused to talk to "Primetime."