The mysterious disappearance of 24-year-old Sydney Marquez has intensified with shocking new details: her car was discovered idling and abandoned outside a derelict hotel just 3 miles from her apartment, CCTV captured a shadowy figure lingering nearby for 7 minutes, and her phone’s last signal pinged over 12 miles away in another part of Houston.

Sydney, a former Texas A&M University student from El Paso, was visiting friends in Houston when she vanished on December 11, 2025. Last seen walking near the 9100 block of Bellaire Boulevard in the city’s Chinatown area around midnight, she left her vehicle running with her phone inside – an out-of-character move that immediately raised alarms.

Her parents, Raul and Luz Marquez, told investigators they are “completely clueless” about where she might have gone or why. In emotional interviews, they described Sydney as struggling with mental health issues and not taking her medication at the time, adding layers of concern to the case. Surveillance footage shows her heading toward her hotel but veering off course, with no clear explanation.

The discovery of her car outside an abandoned hotel has fueled speculation. Authorities believe the location, roughly 3 miles from her temporary residence, could hold clues, but the eerie CCTV of a shadowy figure loitering for exactly 7 minutes – without approaching the vehicle – has sparked theories of foul play or a stranger’s involvement. Meanwhile, her phone’s final ping, detected over 12 miles distant, suggests possible movement or someone else handling the device.

Houston Police Department continues the search, coordinating with family and nonprofits like the AWARE Foundation. No evidence of abduction has emerged, but the combination of an unlocked running car, distant phone signal, and mysterious figure has left investigators puzzled. Friends waiting at the hotel grew worried when she never arrived, prompting the missing person report.

Sydney’s case highlights the vulnerabilities faced by those battling mental health challenges, especially while traveling. Her family pleads for public help, urging anyone with dashcam footage or sightings to come forward.

As the investigation enters its fourth week, hope persists amid growing fear. The abandoned hotel site has been thoroughly searched, but questions linger: Did Sydney walk away voluntarily? Was the shadowy figure watching or waiting? And what drew her phone so far afield?

The Marquez family remains vigilant, sharing updates and flyers. In a city as vast as Houston, every detail counts in unraveling this haunting mystery.