Ghost Hunters' season four finale takes the TAPS team to Portsmouth Harbor Lighthouse and Fort Constitution in New Castle, NH. The 48-foot cast-iron tower was erected in 1771, with the grounds covering approximately 2 acres including Fort Constitution and the Keeper's Quarters. After years of late night reports from the Coast Guard and other witness accounts, the members of the Friends of The Portsmouth Lighthouse want to know if the lighthouse and surrounding grounds are truly haunted. Jason and Grant will be facing one of their most interesting challenges as they explore the Portsmouth Harbor Lighthouse, the Fort Constitution and the Keeper's Quarters.

TAPS goes to the Maritime Museum of San Diego to investigate the oldest active ship in the world, the star on India, and her slip mate, the Berkeley.

TAPS explores the Clovis Avenue Sanitarium, a sixty-six year-old, 8,000 square foot mansion. The former sanitarium opened in 1942, and stayed in service up through 1992. In that time, countless patients passed through the halls, and thousands died there.

The TAPS team takes a look back at their most memorable cases. Hosted by Josh Gates.

All the shocks. All the frights.All the details hashed out in a roundtable discussion about the Ghost Hunters live event.

Eureka's Colin Furguson joins the team for a startling investigation aboard the USS Hornet.

Springfield, MA: THEODORE'S/SMITH'S TAPS investigates a landmark pool hall in team member Steve Gonsalves' hometown. Over the years, the first floor fronted several retail clients, but is now a tavern called Theodore's. Though two separate establishments, Theodore's and Smith's have a common problem; they both experience intense paranormal activity. Now, their owners are working together and asking TAPS to diagnose their decades-old problem. Leominster, MA: HAUNTED VICTORIAN II TAPS investigates claims of paranormal activity in a local family's 19th century Victorian home. After their investigation, the team left with the belief that something other than the family was living in the home.

Dayville, CT: Tracy house Heather Tracy and her family moved into her ancestor's property two years ago. There were always reports of odd activity and it soon became apparent to her that there was something more to the stories. Appleton, NY: Haunted Winery Previous owners saw their wives die in the house from illness. And one owner accidentally shot and killed his son while another died under suspicious circumstances. By 1933, the Sisters of St. Joseph became the new owners and used the estate for decades as a nuns' retreat, a camp for girls and a training school for the deaf. Now, the winery has become a part of an eerie lore.

TAPS returns to Louisiana to investigate the historic Oak Alley sugar plantation in Vacherie. When Jacques Telesphore, the businessman who built the house, died of tuberculosis in 1848, his family couldn't maintain the business, and had to sell the property.

TAPS is in Florida to investigate an inn that is a hotbed of paranormal activity. This unique St. Petersburg property consists of two multi-story Victorian manors: the Pink House and the Purple House. They were both built in the late 1800s, and are believed to house more than just customers. Elsewhere in St. Petersburg, TAPS investigates the legendary Renaissance Vinoy hotel, Major League Baseball's favored paranormal getaway. Built in 1924, the Vinoy has always been a preferred vacation spot for the rich and famous. Today, the facility is the visiting-team hotel for the Tampa Bay Rays.

TAPS visits the abandoned (and skeevy) remains of an art-deco masterpiece, Buffalo Central Terminal. The terminal, a 14-story combination office tower/train station, opened in 1929 and closed 50 years later. After falling through the hands of various owners, the Central Terminal Restoration Corp. acquired it in 1997. In the years since the Terminal's abandonment, it has become a potent source of paranormal stories. Local urban explorers and less respectable paranormal investigators would break into the property to look around, leaving in a hurry and with numerous scary experiences. One volunteer was alone in third-floor offices, and saw two people (described as being dressed in old-fashioned clothing) standing at a water fountain. When he stepped closer, the people and the water fountain disappeared. The experience shook the volunteer so badly that he will not enter the building alone. There are cold spots widely reported throughout the terminal, especially on the train platforms. Some who have visited have asked the darkness for a response, and gotten a loud bang.

TAPS visits a 16th century North Kingstown, R.I., landmark to solve an awful mystery. The Carriage Inn was built in 1760. Now a busy banquet facility called Hoof, Fin and Feathers, it is the center of mysterious sightings. A woman in period dress (late 1700s, early 1800s) has been seen in the main house's main dining room. In the bar, people have seen a man dressed in black carrying a book. The most disturbing sighting by far happened in the barn, which is now the banquet hall. There, people have reported seeing a young girl who had been burned. Both the cellar and attic inspire feelings of great dread. Several employees have refused to enter them alone. In addition, temperature changes plague the attic. Intense cold will settle onto an extremely concentrated area — someone's face, or even just his or her nose. Owner and head chef Linda Wadensten does not feel threatened, though she does want TAPS to find what is haunting the Carriage Inn. Then, TAPS comes to help a military family living in Groton, Conn. When the Stitelers's four-year-old son first saw the ghost of a child in his room, a boy with black hair and black eyes, he didn't tell his parents. Instead, he mentioned it while he was in the hospital with a brief illness. His mother was surprised that he knew what a ghost was, and wrote it off as an imaginary friend until she told her husband. William went white. He had seen the same figure in their home, and it had terrified him. In addition, the husband has had a sleeping problem in recent months. He wakes up in the middle of the night with a feeling of overwhelming dread and danger, not from a dream, but in the waking world. Invariably, within minutes of waking up with these feelings, he hears toys turn on in his two-year-old's room. He turns them off and tries to return to sleep.

Jason and Grant are called in to investigate a haunt hidden in their own neighborhood — the Slater Mill. In its early years, almost all of the employees at the mill were children, and the workers were often pushed to their limits. Working conditions were difficult and unhealthy — respiratory ailments and diseases were rife, and the mill was home to many grisly accidents. Then, TAPS goes to Connecticut to unravel the mysteries at the historic Pettibone Tavern. Built in 1780, the tavern originally served as a carriage stop between Albany and Boston during the late 18th century. During this time, it was also supposedly the site of a brutal axe murder, and through the years, employees have consistently reported activity that they cannot explain.

A local preservation society took over this property in 2000, and discovered over 30 boxes of unclaimed human remains tucked away in the basement bathroom. Renovations unearthed remnants of the Episcopal church as well as light fixtures and stained glass that'd been hidden behind the walls and ceilings as if the original funeral director created a building within a building. Many women who work at what is now a museum complain of being followed around the building by someone who isn't there. One in particular believes this feeling has increased 100% since they received an altar from another century-old church. Temperature fluctuations from extreme cold to uncomfortable heat are found throughout the structure. Furniture and doors have been heard moving and the sounds of shuffling footsteps are common. The original funeral director even admitted that doors that he had closed and locked would be found open. Floral arrangements were found rearranged. And on a few occasions he had heard strange voices in the building when there was no one else around.

TAPS investigates Fort Delaware, located on Pea Patch Island. The Island sits in the mid channel of the Delaware River near its entrance into Delaware Bay. Once the location of strategic military defenses, the island is currently owned by the state of Delaware as Fort Delaware state Park. During the American Civil War, Fort Delaware was used by the Union as a camp for Confederate prisoners, in particular ones captured at the 1863 Battle of Gettysburg. Many of the prisoners who died at the fort are buried at nearby Finns Point National Cemetery in New Jersey.

TAPS investigates two locations in New Jersey. First they tackle the Proprietary House, the home of New Jersey's last royally appointed Governor. Next they move on to a 19th Century mill with reports of paranormal activity.

The Taps team heads to the coasts to tackle with two investigations. First they travel to Massachusetts to visit the Colonial Inn at Cape Cod. Then they head over to California to investigate the Moss Beach Distillery.

Jason, Grant and their team head to New England to answer a call from a terrified family plagued by mysterious apparitions. During their investigation, TAPS uncovers shocking evidence of paranormal activity in the home. From there, they take on claims at the Palace Theater in Manchester, N.H., a former vaudeville stop that hosted performances by Bob Hope, the Marx Brothers, Jimmy Durante and Harry Houdini. Today, staff at this historic playhouse report endless paranormal claims ranging from apparitions to footsteps and slamming doors.

TAPS is contacted by volunteers who are restoring Weston State Hospital. Jason & Grant head to West Virginia to investigate this former asylum that once housed Charles Manson.

TAPS heads to Nevada to visit the famous 100-year-old abandoned Goldfield Hotel and then the Old Washoe Club and St. Mary's Art Center (formerly St. Mary's hospital) in Virginia City.

TAPS investigates the Ruff Stone Tavern in North Providence, R.I. and the Mount Washington Resort in New Hampshire.

TAPS investigates three buildings at the Wright-Patterson Air Force Base in Dayton, Ohio where stories are told of ghostly typists, children's voices, and a haunted elevator.

The team goes to Trinway, Ohio to investigate Prospect Place, a stop along the Underground Railroad during the Civil War. Then they investigate a home in Massachusetts where the owners complain of shadowy figures.

The team travels to Pennsylvania to investigate the Cashtown Inn, a bed & breakfast that was a military headquarters during the Civil War.

The Clapp Library in Belchertown, Massachusetts and a family's claim that they have been haunted for four generations are investigated by the team.

Burlington County Jail in Mount Holly, NJ, which has now been turned into a museum, is investigated. Elsewhere, a Connecticut family's home is investigated.

Fort Mifflin in Philadelphia is investigated. The site was used as a garrison during the American Revolutionary and Civil Wars.