Security guards encounter a door repeatedly opening and slamming shut.

Experts investigate how a boy can twist his head 180 degrees.

Experts investigate footage of an ape-like creature in Russia.

A bizarre explosion is captured that morphs into a sinister black ring of smoke above a California football stadium; experts investigate and uncover an underground network of Satanists with connections to a string of modern-day terrorist plots.

Security cameras capture an empty car moving as if driven by a ghost.

Experts investigate evidence of flying, fire-breathing creatures.

When footage reveals a man's leg taking on a life of its own, it appears that something alien is trying to burst free; cutting-edge science investigates what explains this strange and sinister possession, and what it takes to exorcise the invader inside.

Footage of a fearsome wolf-like creature in the remote wilderness of northern Canada could be evidence of a dire wolf, a prehistoric beast that went extinct at the end of the last Ice Age; experts use cutting-edge tech to investigate if it has returned.

A bizarre, tentacled black mass emerges from the seas on an island in the Caribbean, and on-lookers are horrified as it writhes ashore; experts use cutting-edge tech to investigate the origin of this alien invader.

Doctors discover a mysterious parasitic species inside a man's nose.