The team makes its way to Ireland, to check out Wicklow Gaol, a prison constructed in 1702 that once housed some 780 prisoners during the Great Famine. It's now a museum, but reports have been made of people being pushed or touched by unseen forces, seeing blood on the floor, and witnessing strange shadows and mists.

This week, the GHI team conducts a pair of investigations. The first takes them to the Czech Republic, where a sprawling castle known as Cesky Krumlov has been the setting for numerous reports of supernatural phenomena. Constructed in the 13th century, the castle spans five courtyards, 43 buildings and 15 acres of land, making it one of the largest locations ever investigated by GHI.

This week, GHI investigates the Czech Republic's Castle Houska, a structure supposedly built to keep something in. Legend has it that the castle, dating back to the 13th century, was built over the Gates of Hell and meant to keep evil spirits from escaping into the world. Needless to say, the team is champing at the bit to get a crack at this gothic fortress.

The team arrives in Austria for the first time to investigate the eerie Moosham and Schloss Porchia Castles. First up, is the Moosham Castle, which was built in the 13th century by the Mooshimmer. Moosham Castle was allegedly a torture site during history's bloodiest witch trial. When the archbishop made accusations of witchcraft against certain women it was off with their— well, yeah, you know where we're headed (no pun intended!).

The GHI team heads to Italy for a pair of palace investigations. The first takes them to Fosdinovo, Italy, location of Malaspina Castle. Built in the 11th Century, the structure has been owned by one family for hundreds of years. Pietro, the latest in the line of owners, shows the team around to sites in which visitors have seen shadows, heard screams, and witnessed poltergeist activity like drawers opening and closing on their own.

GHI heads to the southern hemisphere for a pair of investigations in Chile. The first is in El Bosque, where the City Hall has been the site of numerous reported phenomena. Formerly an orphanage, the building also served as a retirment home for Catholic priests, and was used for the torture of suspected communists in the country's 1973 coup.

The Ghost Hunters International team makes its way to Argentina to visit the historic Gran Hotel Viena. The hotel is in disrepair now, but was once rumored to be a compound for Nazi war criminals who had fled Germany. Most significantly, there are conspiracy theories claiming that Adolph Hitler did not, as is popularly believed, commit suicide in a Berlin bunker, but rather fled to Argentina, and to the Gran Hotel Viena. Robb and the rest of the team are very excited to have the chance to seek the spirit of one of history's most notorious figures.

The team's back in Argentina this week with a visit to the Eden Hotel, which many folks claim is the most haunted spot in the country. The hotel opened in 1899 and was a destination for the rich and famous, but is now a museum. Curator Rose Zicari leads the initial tour, detailing phenomena like the sounds of voices and moving shadows. Particularly of note are encounters children visiting the museum seem to have with the ghost of a little girl.

It's time for the Ghost Hunters International team to get ill, as they head out to Sydney's Quarantine Station. Opened in 1833, the location served as an entry point for passengers in which the sick were separated from the well and kept under some fairly harsh conditions. Cases of plague, typhus, cholera, smallpox and Spanish influenza were all prevalent there, and many people died within the station's confines.

A centuries-old prison that was home to rapists, murders, and the criminally insane sounds like a setting right out of a horror movie, but it's a real place - Australia's Port Arthur Penitentiary, rumored to be one of the most haunted spots in the world. As the team descends on the location, Brandy details Port Arthur's history, and a long list of reported paranormal phenomena that includes apparitions, moving objects, footsteps, and even people reporting being touched by spirits.

The GHI team remains in Tasmania to investigate a building that used to be the island's Supreme Courthouse. But its walls also had a darker purpose at one time- it was originally built to be a prison, and execution ground. Then they fly to Malaysia to investigate Kellie's Castle, a fabulous mansion built upon a tragedy- dozens of the Hindu workers died from sickness during its construction.

As the team rolls out, Robb informs us that Dustin won't be along for this particular trip, then tosses it to Brandy, who runs down the history of Costa Rica's San Lucas Island Prison. Built in 1862, it's the Costa Rican equivalent to Alcatraz, and has a dark history. Tour Manager Craig Lapsley meets the crew at the boat that will ferry them to the island, and regales them with tales of prisoner torture and the murder of both a nurse and a priest within the prison's confines.

Sugar was king in the 1800s, bringing immense wealth to the owners of Jamaica's sugar cane plantations. There were 700 plantation great houses, all built on high ground to oversee the thousands of slaves who worked in the fields below. During the slave rebellion of 1831, 685 of the great houses were burned to the ground as hated symbols of the extravagant life styles founded on cruelty. Yet, one of the fifteen great houses which still remained was The Rose Hall Great House, a 6,000 acre and 3,000 slave plantation.

Location: Nottingham, England

This week is a double-header, with the team starting at Margam Castle in Wales. They meet with Geraint Hopkins, a tour guide at the castle for roughly 20 years. They use his expertise to investigate the most active areas.

The team makes their debut in Poland at the Wolf's Lair, Hitler's Eastern Front command post, where he spent roughly 800 days and where the attempt on his life, Operation Valkyrie, failed. Judwiga, the staff historian, tours them around the facility, where eerie noises, voices speaking German, and creepy feelings, as of being watched, abound.

The team goes to investigate some of the boldest claims they've ever faced, in the Fredricksten Fortress in Norway. Robb and Ashley start at the bell tower, a spot where a woman, now known as the White Lady, was said to have killed herself and later, as a ghost, to have pushed a lieutenant to his death. Robb tempts the spirit by standing on the ledge and provoking the White Lady into touching him.

The team heads to Nicaragua, and Susan, after introducing the ghost hunters to her extended family, leads the way. She and Robb check out the Beast Tower in Coyotepe Fortress, where Satanists have been known to perform rituals. They both feel strange sensations and pursue a mysterious noise with the feeling that they're being toyed with. As Joe and Barry investigate the site of an exorcism, they hear footsteps and call on Scott and Paul for backup, who report that one of their cameras has gone out. Revisiting the Beast Tower, Scotty and Joe hear a "Hey," and hope to catch it in analysis.

In Omoa, Honduras, the team heads to Fortaleza de San Fernando, a former fortress and prison with connections to the history of the pirates of the Carribean.

The team heads to Kronborg Castle in Helsingor, Denmark - the setting that Shakespeare chose for Hamlet. Their client, Shane, gives them a tour that includes a massive ballroom, Queen Sophie's room, and a dungeon that has a reputation for bizarre noises and draining camera batteries.

In the countryside of Ukraine lies a castle called Pidhirtsi. Dr. Vita Susak wants to turn the erstwhile tuberculosis hospital and Nazi experiment grounds into a museum, but she's concerned about the paranormal activity there. When GHI arrives, they begin by investigating tales of the nobleman who lived there who allegedly immured his wife because she was unable to have children. Visitors have spoken of seeing a White Lady - thought to be the nobleman's wife - and while Susan looks for her, she's hit by a dizzy spell, hears someone say "Oi," and feels something touch her face. While Britt and Joe seek the White Lady in the chapel, they also feel lightheaded. In an EVP session, they ask for a knock, and get one. They ask again, and again get a positive response.

The team seeks the source at Fursteneck Castle in Germany. The legend of the place is that a medieval knight interred his cheating wife is its walls, and an apparition, thought by many to be her, is often seen in this castle-turned-hotel.

Can a house ruin a man’s life? According to Johan Vlemmix, owner of what is referred to as the most haunted house in the Netherlands, it can. He bought the house just over a year ago, and since that time, all aspects of his life have gone downhill. The previous owner concurs – his own life is in shambles, he says, solely because of the house. Johan is grateful to have GHI present, and they, in turn, do their best to get to the bottom of the strange phenomena to which the house is prone.

Europe's largest undestroyed fortress - the Petrovaradin Fortress in Novi Sad, Serbia - is bound to have a few stories to tell, and the GHI team want to hear them. Alen Panikovic, who works at the now-museum, shows the team the grounds, including a prison, a barricade area, an execution wall, and a tunnel system 16 kilometers long. The facility is so large that their normal equipment won't do the trick, but luckily Paul is able to rig a device for each of the investigators so that they can carry DVs, audio recorders, EMF detectors - the whole toolkit - on one hand-held rig. Genius. Barry warns them to be careful of the fortress's dangers, including collapsing tunnels, and with that, the explorers set off.

The destination this week is Scotland, starting at Usher Hall in Edinburgh.

The GHI team head to Puerto Rico, but they're not expecting a relaxing time at the beach. Debbie Molina Ramos has called them here to see if visitors to her facility, the San Cristobal and El Morro Fortresses in San Juan, are safe from the paranormal activity they've reported.