On Friday, June 9, 2017, 26-year-old Ying Ying Zhang was working in the lab with her colleagues at the Department of Natural Resources and Environmental Sciences within the College of Agriculture, Consumer and Environmental Sciences at the University of Illinois, Urbana, Champaign.

They had finished their field work, studying photosynthesis and crop productivity, and they were packing up some damaged equipment to send out for repair.

At about noon, Ying Ying said that she had to meet a property manager to sign a lease on a new apartment and said she would be back.

The hours passed, but Ying Ying never returned to the lab. Her colleagues grew worried and called her cell phone but got no answer.

Finally, they left the lab and went to her apartment, thinking that maybe she had gotten sick. They knocked on the door, but nobody answered there either.

Ying Ying was not the type of person to just blow off her responsibilities and had only been in the country for about six weeks, so she didn't really know many people.

Her colleagues thought that her disappearance was suspicious enough that they went to the University of Illinois Police Department and reported her missing.

Officers made entry into her apartment to make sure she hadn't suffered an accident inside, but the residence was empty.

They checked a handful of other places that the young woman was known to frequent, but they didn't find her.

It seemed that Ying Ying had just vanished. This is Monsters.

Ying Ying Zhang was born on December 21, 1990.

She completed her master's degree in environmental engineering at Peaking University and did some work as a research assistant at the Chinese Academy of Sciences in Beijing.

Ying Ying had a full life in China. She had a fiance who she had met years before at university and she was the singer in a band called Cute Horses.

Despite that, she left home and went to the United States as a visiting scholar at the University of Illinois Urbana Champagne.

She arrived in Illinois in April of 2017 and planned to enroll in a Ph.D. program that fall. She had her own apartment nearby and it was the first time she had lived on her own.

The day after she was reported missing, officers learned that she was supposed to meet the property manager at a new apartment.

When they questioned him, he said that he had received a few text messages from her when she was on her way, with the last one saying she would be there at about 210 pm.

When she hadn't shown up after 230, the manager texted her to see if she was still coming but got no reply.

Investigators made an emergency cell record request to see if her phone was pinging anywhere but they didn't find anything.

They also started looking at surveillance from the more than 2000 surveillance cameras around the university.

Investigators found footage of Ying Ying getting on one bus on her way to the new apartment.

In the video, she can be seen sitting down and then sending a text message.

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