“The world is big enough for us. No ghosts need apply.” So said Sherlock Holmes when talking about the possible existence of vampires. Star Trek agrees with Holmes’ skepticism of the supernatural. Throughout the franchise’s history, however, there have been seemingly supernatural happenings, most of which are explained away by science. With Halloween just around the corner, we thought now would be a good time to test your knowledge of all that is spooky in the Star Trek canon. Do you dare?

In the Enterprise (ENT) episode “Impulse,” our intrepid crew encounters a ship full of Vulcan zombies. What caused these most logical of beings to join the ranks of the walking dead?

The unfortunate Vulcan crew was affected by Trellium, a mineral they had lined their hull with to negate the effects of anomalies while in an area of space known as the Expanse. Turns out not to have been such a great idea!

In “The Tholian Web,” a third season episode of The Original Series (TOS), Captain Kirk is believed lost with the Enterprise’s sister ship, the Defiant, and a memorial service is held for him. But then Uhura sits down to brush her hair and finds Kirk’s apparition staring back at her from the mirror! Her attempt to report the incident earns her a nice rest - strapped to a bio bed in sickbay, since there are no rooms with padded walls on the ship. Uhura’s not crazy, though. How is this possible? Bonus points if you know what the Defiant’s ultimate fate was.

Kirk and the Defiant were pulled into another universe and the captain was trapped in interphasic space. When Spock and Co. are unable to retrieve him, they prematurely decide to give up on him. But then Scotty, and eventually the entire bridge crew, see their captain floating before their eyes, proving Uhura’s sanity, and they realize he is not beyond rescue. The Defiant, just as Kirk is saved, disappears forever. Except it doesn’t. It seems the ship went permanently into the Mirror Universe and BACK IN TIME, finding itself in the two-part episode “In A Mirror, Darkly” on ENT.

The episode “Devil’s Due,” in The Next Generation (TNG), found Ventax II being claimed by Ardra, the planet’s version of Earth’s Devil. What was the centuries-old deal that made her think the planet was hers to claim?

According to legend, the Ventaxians had petitioned Ardra to grant them 1,000 years of peace and tranquility and an end to war, poverty and famine. In exchange, at the end of that time, Ardra would return to plant her devilish flag on the planet and enslave its people. In the end, Captain Picard’s pragmatic world view won out and Ardra was proved a fraud.

“The Visitor,” a fan favorite Deep Space Nine (DS9) episode, focuses on Jake Sisko’s life after his father is killed in an accident aboard the Defiant. Except Jake keeps seeing him every so often, as if seeing a ghost. Of course, this is Star Trek, so let’s assume Jake wasn’t being haunted. In that case, what the heck was going on?

It turns out that Ben had been trapped in a temporal inversion, causing him to fall in and out of sync with normal time and disappearing into subspace after a brief period in normal space. He wasn’t a real ghost but he did manage to scare the bejeezus out of his son!

Star Trek: Voyager’s (VOY) “The Haunting of Deck Twelve” finds the crew of the titular vessel shutting down main power. Neelix keeps the Borg children occupied by telling them the tale of Deck Twelve, which Naomi Wildman claims to be haunted. But it’s not a ghost inhabiting the halls of Voyager. What is?

Several months earlier, Voyager accidentally picked up a life form from a Class J nebula. In a gambit to get Janeway to take it back home, it caused all kinds of mischief, short of TP-ing the captain’s quarters. Once it was contained, the Voyager crew found it a new home.

In ENT’s “Oasis,” the crew learn of a haunted transport vessel that has crashed on a nearby planet. When they arrive, they find no power signatures or – and this is important – life signs. As they investigate, the away team hear strange noises and see mysterious moving shadows. Did I mention there were NO LIFE SIGNS? What gives? (And who is the Trek alum guest starring in the episode?)

A dampening field had hidden the life signs from the Enterprise’s sensors. But there’s more to it than that. Though our heroes meet the entire ship’s crew, only two of them are truly alive. No need to call the Ghostbusters, though. The others are merely holograms that Ezral, played by DS9’s Rene Auberjonois, programmed to keep his daughter, the only other survivor of the crash, company.

TNG’s “Thine Own Self” was inspired by Mary Shelley’s seminal novel Frankenstein. In the episode, Data comes upon a village on an alien planet with no memory of who he is or how he got there and unable, at first, to speak. What caused this condition?

Data had been sent on a mission to retrieve a deep space probe that had crashed on the planet. The probe had been leaking radiation and, Data being an android, he was the most logical crew member to retrieve it. Unfortunately, there was a power surge as he was collecting information from it and his positronic net had been overloaded. That doesn’t explain the bolts sticking out of the sides of his neck, though.

The staff here at Daily Star Trek News wish you a safe and happy Halloween!