Amanda Antoni's husband finds her body in their basement with blood everywhere. The scene confounds police: Was it foul play — or a tragic accident?

When an aristocrat and his entire family disappear, the authorities unearth something horrifying.

Twenty-year old Josh Guimond leaves a college party without a word and is never seen again. Two decades later, his loved ones just want answers.

After rushing from his home, Rey Rivera disappears. Days later, his car is found — and a strange sight at a historic hotel triggers a baffling mystery.

Tiffany Valiante, a promising young athlete, is struck by a train four miles from home. But was her death a suicide or something more sinister?

After checking in at a luxury hotel with no ID or credit card, a woman dies from a gunshot. Years later, her identity — and her death — remain a mystery.

A beloved father is brutally mutilated, but his presumed killer, a woman he knew from high school, escapes without a trace.

After a teen finds an embalmed head in the woods, investigators uncover a possible connection to a black-market organ trade as they try to ID the victim.

Patrick Mullins' unmanned boat is found miles from his home. When his body surfaces a week later, authorities are left with more questions than answers.

Paranormal researcher Don has an odd co-worker: an entity named Becky. A parapsychologist observes Don and Becky at work and is stunned by his findings.

Amid eerie sightings of a tall, winged humanoid creature with red eyes, paranormal investigators explore the Mothman's seeming link to major disasters.

For decades, a wave of cattle mutilations executed with near-surgical precision has plagued the US. Are extraterrestrials behind these gruesome acts?

In 1947, an unidentified flying object crashed near Roswell, NM. Was it a spy balloon or an alien encounter? UFO experts unravel the iconic mystery.

Residents of Berkshire County, Massachusetts, recall their baffling, terrifying experiences with a UFO on the night of September 1, 1969.

Bigfoot, orbs, UFOs, poltergeists and skin-walkers. For these Navajo Nation rangers, paranormal activity is just part of the job.

A massive earthquake and tsunami devastated Japan in March 2011. Residents share stories of the spirits they encountered in the wake of the disaster.

London, 1888. The city is gripped by a string of murders, each more gruesome than the last. Experts delve into one of history's most notorious mysteries.

Over 300 residents of western Michigan report seeing unearthly lights on the night of March 8th, 1994. Decades later, the event remains unexplained.