Grey's Conspiracy: The team investigates disturbingly similar stories of alien abductions from two different countries before tracking down some potential proof in Mexico. (S3, ep 2)

Giant Triangles: The team uncovers rare footage of floating giant triangles hovering over cities. Could these strange sightings be extraterrestrial in origin? (S3, ep 1)

Murder On Miguel Lane: When three teenage friends were found murdered in Arlington in 1985, a thorough forensic investigation turned up a highly unlikely culprit. (S3, ep 4)

Innocent Bystander: When a drug dealer and his girlfriend are found murdered in their apartment, a bloody print leads investigators to a killer who defies belief. (S3, ep 3)

Left For Dead: In 1997, Henry Caneva was found dead after he and his wife were attacked in their home. With little to no evidence, how did investigators nab his killer? (S3, ep 2)

Perfect Family: A family are found murdered in their home. Only their 20-year-old daughter has survived. Investigators wonder who would kill this seemingly perfect family. (S3, ep 1)

UFO Surveillance: The team investigates videos indicating a strong UFO surveillance presence at weapons laboratories. (S3, ep 13)

First Response: The team attempts to uncover the US military's first responses to UFO encounters, leading them to revisit a suspected UFO crash site in California. (S3, ep 12)

Dark Presence: The team investigates growing numbers of flying orbs sightings, with witnesses also experiencing odd dreams, premonitions and deep fear. (S3, ep 11)

Area 52: Area 51 is considered the ultimate top secret facility, but there is another military site, known as Area 52, where strange phenomena have been witnessed for 10 years. (S3, ep 10)