The team goes to Trinidad to probe claims concerning the ghost of a cocoa plantation owner in the Season 3 premiere.

A former leper colony is probed on Trinidad's Chacachacare Island; the ghosts of four murdered workers are sought at a meat packing plant in Argentina.

The team heads to Barry's homeland of Ireland to investigate two local infamous cases. The first is at Roe Valley Hospital, a site that began as a workhouse - a facility where the homeless were forced to perform grueling labor - until it was transformed into a hospital by Dr. Robinson, a woman who is said to haunt the grounds today.

The team goes to Britain in search of a she-wolf.

Probing Castle Rushen on the Isle of Man, where sightings of a ghostly girl have been reported. Also: the team goes to New Zealand to investigate a hotel, the site of an unsolved murder.

The team probes New Zealand's Napier Prison, where phantom footfalls and disembodied threats have been heard and doors have allegedly closed by themselves.

Claims of paranormal activity and legends of a magical stone are probed in Peru's Chavin ruins.

The team heads to the Fort of Fenestrelle in Turin, Italy. This massive fortress will require the team to climb 4,000 steps to reach the investigation site. There is a prison in which hundreds died, including a man who had been forced to hide his face behind an iron mask as punishment for his crimes. Locals believe this man is haunting the prison and fortress- and one witness claims to have seen the apparition of the man with burning red eyes! In the officer's prison, people speculate that the man with the iron mask was a relative— either an identical twin, illegitimate child or distant relative — to the king. As he was a threat to the crown, he was imprisoned and forced to cover his face. A resident walking his dog once saw the man with the iron mask, and his dog went crazy over it.

In San Ignacio, Belize the team investigates caves that the ancient Mayans believed were the first of nine layers to the underworld. The caves were the sites of numerous human sacrifices, including that of the Crystal Maiden, whose bones have been there so long they have crystallized into the cave floor. Claims at the cave, as reported by cave guide Emil Gamez, include chanting noises, balls of fiery light and spirits that pass through people's bodies. In the tomb-like area of the Crystal Maiden people feel strange energy, a sense of unwelcome and glowing lights around the Maiden. Next the team investigates a 14th century mansion in Queaux, France where a ghost named Alice is haunting the women visitors to the home. She died in the 1920's of a kidney infection and now it seems that any woman who stays in Alice's room gets the same infection! Even the homeowner's daughter ends up in the hospital. How creepy! Full body apparitions, voices, touching, violent noises and shadows add to the mystery.

The team tries to help a man who is being tormented by spirits from the Mayan ruins of Cahal Pech; one team member takes part in a ritual to contact Mayan spirits.

The team investigates an abandoned all girls' school in American Samoa; It is believed that the Samoan Chief possessed and killed schoolgirls.

The team heads to Belgium seeking the ghost of a fallen soldier. Then, they head to Frankenstein's birthplace.

The Ghost Hunters International team travel to Lower Fort Garry in Manitoba, Canada, which was originally built to protect the fur trade. Paranormal activity has increased in recent months! People have spotted the apparition of a little girl in the guest cottage and a figure of a man and a woman in the prison where a guard once killed himself. From the blacksmith's shop people hear hammering noises and this is the site of an explosion that killed the blacksmith and his son. People have seen a man looking out the window of the warehouse. A security guard confronted a man walking around upstairs, and when he asked him to leave the man walked out through the wall! In the sick house, once used for tuberculosis patients, workers found the house trashed and a little girl crying in the corner, only to have the girl disappear just after! Why is this suddenly happening? Hopefully the team can answer some questions. Next the team heads to British Columbia, to Hell's Gate Airtram, the site of the construction of the Canadian Pacific Railway. Rumor holds that for every mile of track that was laid, 3 Chinese workers were killed. Reports are of apparitions, sounds of shouting and screaming and the figure of a man in the dining room who is smoking a cigar. Products have fallen off walls, people hear footsteps and voices, and someone saw a dark shadow with fierce Doberman dogs with them. In the terminal, guests have felt people playing with their hair. The activity has kicked up during the winter season and the operators of Hell's Gate are concerned they won't be able to re-open in the spring.