By all accounts, it was a huge Halloween party.
More than 600 people, most of them in costume, gathered at a rural farmhouse in Monroe County, Michigan, on Oct. 26. There were food trucks, booths and a live band.
One of the partygoers was 22-year-old Chelsea Bruck. Dressed as the Batman villain Poison Ivy, she wore black leggings and a green ivy leaf-covered top. A long black and purple wig covered her blonde hair.
But when the party was over, Bruck had vanished without a trace, leaving behind a frantic family desperate to find answers. Her bank account is untouched; her social media accounts have not been accessed.
“There is no way she just walked away on her own,” Bruck’s sister, Kassandra, tells PEOPLE. “We’re a very close family, and we talk all the time. She was not unhappy or wanting to walk away. I’m getting married in two months and Chelsea is in the wedding. On the morning before she disappeared, she sent me a Facebook message saying, ‘I can’t wait until you get married.’ She wouldn’t go somewhere for this long without telling us.”
In a Nov. 5 press conference, police said that they interviewed 138 people and received more than 275 tips, many from drunken partygoers.
“Take 600 people and put then in costumes,” Monroe County Sheriff Dale Malone told reporters, “and then have those people relay stuff back to us. That’s the problem; that’s what we’re dealing with right now.”
But one promising lead emerged: a witness reported seeing Bruck having a cordial conversation with an unidentified man. The two walked towards where the cars were parked – but it’s unclear whether they got into a car together.
Based on the eyewitness description, a police artist drew a sketch of a man with dark hair and glasses – but it may not be helpful. “Everyone was in costume,” says Kassandra. “That adds to the confusion. We don’t know if his hair is really that color. We don’t know if the glasses were real. We just don’t know anything.”
Another detail soon emerged: during the party, Bruck had run into a wooden post and gashed her head. Friends offered her a ride home, but she declined. Throughout the evening, she made several calls on other people’s cell phones.
Bruck’s family has taken their search online. They have created two Facebook pages. Find Chelsea Bruck is a page where people can send in their tips. Help Find Chelsea Bruck shares latest information about the search. A GoFundMe page has been set up for search expenses.
“We are going to keep looking,” says Kassandra. “And we’re not going to stop searching until we find her.”