Season 4 kicks off with a probe of Philadelphia's Fort Mifflin, a garrison used during the Revolutionary and Civil Wars, concerning claims made by visitors and facilitators of the historic site.
The team probes the Burlington County Prison Museum, a historic jail in Mount Holly, N.J. Also: a Connecticut home is investigated regarding claims involving disembodied voices and objects that move of their own accord.
Phenomena attributed to Clapp Memorial Library and claims concerning a family home purportedly haunted over four generations are investigated in Massachusetts.
The team seeks out disembodied voices and apparitions of soldiers at Cashtown Inn, a bed-and-breakfast in Gettysburg, Pa., that once served as Civil War headquarters.
Prospect Place, a stop along the Underground Railroad in Trinway, Ohio, is probed regarding claims of phantom scents and spectral whispers. Also: the team tries to help a Massachusetts family purportedly plagued by shadowy figures.
The team probes three buildings at the Wright-Patterson Air Force Base in Dayton, Ohio, for claims concerning phantom typists, an elevator with a mind of its own and children's laughter---sans the children.
Paranormal claims concerning the Ruff Stone Tavern in North Providence, R.I., are probed. Also: the team visits New Hampshire's Mount Washington Resort, where the staff has encountered cold spots.
A New England home is probed regarding claims made by the family. Also: the Palace Theatre, a former vaudeville destination in Manchester, N.H., is investigated.
Cape Cod, Mass., is visited for an investigation of the historic Colonial House Inn. Also: the team searches for spirits at California's Moss Beach Distillery.
Two probes in New Jersey have the team checking out the Proprietary House, home of the state's last royally appointed governor, along with a 19th-century mill.
Paranormal claims regarding Slater Mill in Pawtucket, R.I., are investigated. Also: Connecticut's Pettibone Tavern, allegedly the site of an axe murder, is probed.
A Rhode Island banquet hall, formerly an inn that was established in 1760, is probed regarding spectral sightings and claims of cold spots in the attic. Also: Groton, Conn., is visited for a home investigation.
The team boards ships docked off of San Diego to probe paranormal claims pertaining to the Berkeley, a 1898 steamboat ferry, and the Star of India, the oldest active ship in the world.