The team visits San Ignacio, Belize, to look into claims tied to the Actun Tunichil Muknal cave. Later, the Chateau de Fougeret is investigated in Queaux, France.
Barry returns to Northern Ireland to investigate the former Limavady Workhouse, which was later converted into the Roe Valley Hospital before closing in 1997. GHI also visits Spike Island, nicknamed Ireland's Alcatraz.
GHI investigates a former leper colony on Trinidad's Chacachacare Island. Then they fly to Argentina to look into the claims of paranormal activity said to be caused by the ghosts of four murdered workers at the Frigorifico Meat Packing Plant.
GHI returns for its third season in the rainforest of Trinidad to search for the spirit of Count Lopinot, a cruel slave master, who is said to rise from his grave at his former cocoa plantation La Reconnaissance.