When it comes to the terror tour de force, the new Ghost Ship Harbor in Quincy will take some beating. This macabre theme park is set on the USS Salem — a battle class cruiser, long retired as a museum ship and the United States Naval and Shipbuilding Museum’s centerpiece.

Through October, however, the grand ship is the last refuge as a zombie plague befalls mankind. As is always the case, some idiot zombie gets on board and bloody mayhem ensues.

“A big part of the success to doing a haunted house is having a backstory that fits the setting,” says creator Jason Egan, a top player in the horror biz who created the long-running Fright Dome in Las Vegas. “Crazy killer clowns on the USS Salem just didn’t make sense. Zombies and a plague make sense.” 

The Ghost Ship Harbor welcomes all ghostbusters over the age of 12 — sparking the interest for anyone like Egan, who’s been a big horror fan since elementary school. And for Egan, he eventually turned his fandom for the premeditated paranormal into a career.

“I’ve worked with the ‘Halloween’ movie people, I worked with the ‘Texas Chainsaw Massacre’ people, and I worked with [‘Night of the Living Dead’ director] George A. Romero ­— he basically started the whole zombie thing.”

Zombies are one thing, but what’s got teeth-a-chattering is the rumor that the USS Salem, which was used in Chris Pine’s Disney film “The Finest Hours,” is actually haunted. The ship was featured on the television show “Ghost Hunters” and in Sam Baltrusis’ “13 Most Haunted in Massachusetts.” Like most similar battle class vessels, the Salem had an infirmary and, as a city on the sea, it served as a morgue. Its nickname, the Sea Witch, which honors its namesake Massachusetts’s town’s history, doesn’t ease fears. 

Egan’s not discounting the rumor, but he just wants people to have fun: “It’s a whole night of terror for anyone,” he says. “And it’s good value!”

Ghost Ship Harbor runs through Oct. 31. Tickets start at $29.99, ghostshipharbor.com