If there's something weird, and it don't look good...

Well, you may want to get whatever that is checked out, especially if it's an invisible man sleeping in your bed. But what's still looking great is Ghostbusters, 40 years after the comedy starring Bill Murray, Dan Aykroyd and Harold Ramis as parapsychologists who go into business for themselves first hit theaters.

"It's got lots of laughs, lots of special effects, family picture," Aykroyd humbly described the Ivan Reitman-directed film on The Tonight Show ahead of its June 1984, release. "And we're very, very excited. It's gonna be a good one."

Call it fate, call it luck, call it karma: Ghostbusters was the top-grossing movie of the year in the U.S. and took in almost $300 million worldwide.

"Well, I knew it was going to be a huge movie," Murray quipped on TODAY in 2014. "At that point we were still watching Yankee Doodle Dandy on TV, so I thought we had a shot."

Meaning, he had no idea that the film's blend of improvisational humor and supernatural scares was going to cause a cultural earthquake of biblical proportions. (Last we checked on Instagram, dogs and cats are living together.)

"Even with Bill and Ivan's success, it was like, 'What is this? A comedy? Sci-fi?' It was almost unclassifiable," Annie Potts, who played prickly receptionist Janine, told Entertainment Weekly in 2014. "I'd never seen anything like it. I thought, this is just going to be totally awesome or totally awful."

But much like the coming of Gozer, a lot of pieces had to be in place to make this legitimate phenomenon possible. So while you still can't see the storage facility, we've got a guide to the secrets of Ghostbusters right here:

1. Dan Aykroyd had reason to believe there's a lot going on off the mortal coil, being the great-grandson of dentist/spiritualist Dr. Sam Aykroyd and son of A History of Ghosts author Peter H. Aykroyd. 

So, he tackled writing Ghostbusters with gusto.

His dad's book was "about mediumship and transmediumship and the afterlife and survival of the consciousness after death, so that was the kind of stuff I was reading as a kid," Aykroyd told Entertainment Weekly in 2014. "I originated Ghostbusters based upon reading that material and the real work of J.B. Rhine and [William G.] Roll and the Maimonides Dream Lab—real scientists who were into this. I took that from my family history, my family business, and married it with the ghost comedies of the 1930s."

2. Aykroyd was writing the script as a project for himself and fellow Saturday Night Live alum John Belushi, but the comedy legend died of a drug overdose on March 5, 1982.

"When the keyboard lit up at the office like a Keno board, telling me that he was gone," Aykroyd said on the Howard Stern Show in 2015, "I was writing a line for him."

After which, he took it upon himself to break the news to Belushi's wife, Judy Jacklin. "I had to get to her before it was public," he explained, "so I ran from our office on 155th down to her place on Morton Street." He got there just as a newspaper truck was dropping off the latest edition, which screamed, "Belushi Dead at 33" on the front page, so he was just in time to spare Jacklin the 1982 version of a breaking news push.

3. The script lay dormant for awhile before Aykroyd envisioned Bill Murray taking on the role originally intended for Belushi. Then he pitched the project to Ivan Reitman to direct.

"I read it, and it was sort of a futuristic thing and it was competing groups of Ghostbusters and out in space," Reitman, who died in 2022, recalled to EW. Aykroyd insisted it never went to outer space, but, rather, "inner space."

Associate producer Joe Medjuck concurred with Reitman that there were "lots of Ghostbusters" and "half of it took place in another dimension." But while it seemed like a completely un-filmable movie, they loved the general premise.

4. Reitman and Aykroyd then brought the film to Harold Ramis—who was in Reitman's 1981 comedy Stripes with Murray—and he signed on.

With multiple comedy titans on board, Reitman and Medjuck pitched Ghostbusters to Columbia Pictures president Frank Price, who asked how much it would cost—$30 million, they guessed—and gave it the greenlight in May 1983.

Incidentally, Price wanted it for a June 1984 release, which gave the team 13 months to basically create the movie from scratch.

5. Reitman suggested that the Ghostbusters start out as university professors and the story be set in Manhattan, according to Medjuck.

Of course, you never see them teaching, which is part of the reason why Dean Yeager (Jordan Charney) boots Murray's Dr. Peter Venkman, Aykroyd's Dr. Ray Stantz and Ramis' Dr. Egon Spengler off campus—which is never referred to by name but the exteriors were shot at Columbia University. 

6. George Lucas' Industrial Light & Magic was the biggest special effects outfit of the day, but those wizards were busy with Indiana Jones and the Temple of Doom. So, the Ghostbusters team hired Richard Edlund, who had just finished Return of the Jedi.

"About 80 percent of the shots were take-1s. We just didn't have more time to do any more. The same with the animation," Edlund told EW, acknowledging the compressed timeframe he was working with. "The animation of the terror dog is a little on the funky side, like the scene where the dog busts out into the hallway."

His team at Boss Films still got the job done, but they lost the Best Visual Effects Oscar to the guys from ILM.

7. They almost couldn't call it Ghostbusters because Taft Broadcasting owned the rights to that name thanks to a 1970s CBS sitcom called The Ghost Busters, but Columbia was able to secure what was Aykroyd's original title.

Yet, just in case, there are outtakes of Peter, Ray and Egon saying the "Ghost Blasters" are ready to believe you.

8. Aykroyd also initially intended for his Trading Places costar Eddie Murphy to round out the crew, but Murphy opted to play Axel Foley in Beverly Hills Cop instead.

"It wasn't like I turned it down," Murphy explained on The Tonight Show in 2019, "inasmuch as I wasn't available."

His own franchise-spawning movie came out Dec. 5, 1984, and was the only release of the year to make more than Ghostbusters' $229 million, once you added in the money it made in 1985 for a total of $235 million. 

9. According to Ernie Hudson, the role of steady-paycheck-seeking Ghostbuster Winston Zeddemore that was written for Murphy was much meatier when he first signed on, and his work started on page eight.

But the day before they started shooting, he told EW, he got a new script and "now the character came in on page 68. It was pretty devastating."

Reitman explained that they "broke down the characters to be parts of the human body: Harold was always the Brain, and Aykroyd was the Heart, and Bill was the Mouth." Hudson's Winston was "the voice of the common man, someone who was not involved but could ask the questions that a normal audience would ask."

Hudson admittedly still wondered 30 years later what playing the original role could've done for his career.

10. Sigourney Weaver auditioned for the role of cellist Dana Barrett, resident of the corner penthouse of Spook Central, because she loved doing comedy and no one was offering the Alien star those types of roles.

"It was her idea, by the way, for Dana to be a terror dog," Reitman recalled to EW. "She said, 'I should get possessed,' and then she got on my coffee table on all fours and started howling like a dog."

11. Reitman provided the guttural voice of Zuul that emanated first from Dana's refrigerator and later from her clenched teeth once the demon had her in its clutches.

12. Though Murray didn't work on the script with his costars—and didn't even return to New York until the very day they were ready to film him—he hit the ground running and improvised a number of Venkman's most memorable lines.

Which is all of them.

"I've made five movies with Bill, including the two Ghostbusters," Aykroyd told EW in 2014, before they'd made three more, "and his work gets done in the shooting process. But he's as important at script-writing as any of us were."

Added Reitman, "People would think of things, we would try things on various takes. My job was always to continuously edit while we were working, as the thing evolved."

13. Rick Moranis wasn't the first choice to play Dana's neighbor, perpetually locked out accountant Louis Tully (making the whole Keymaster thing extra funny).

Reitman wanted John Candy, but the Stripes actor didn't like the treatment, the director recalled. Candy's fellow SCTV alum Moranis, however, loved it and said yes within the hour.

He wasn't credited as a writer at the time, but Moranis—who stepped back from acting to focus on his kids after his wife died in 1997—also contributed a bunch of his own material.

14. While Reitman and Medjuck recalled Murray and Aykroyd being treated like kings of New York, beloved from their days as locals on SNL, Murray remembered the production keeping him on a bit of a leash.

"All I ever do is make some movies that made a lot of money, now leave me alone, I want to have some fun," he told Blank on Blank in 1988. "On Ghostbusters they had somebody following us. Following us. You walk down the street, you turn around and somebody would duck into a doorway. Just to control us and make sure we didn't do anything too weird."

He added, "It's like, 'What the hell.' I didn't get into this position by being like a stiff sitting on the set in a folding chair. I did it by walking around on the streets and stirring things up."

15. Murray's reminiscences of what they were able to get away with grew fonder over the years. 

When they shot scenes driving the Ectomobile, aka the Ecto 1, they'd just keep going. "We'd just run around Chinatown," he recalled on TODAY in 2014, "wherever we were, running red lights, wrong way on one-way streets."

16. Yet Murray's costars looked back fondly on his predictably unpredictable antics during filming.

"If he wasn't shooting," Weaver told EW, "I think he could easily end up spending the day with someone who came by to ask him something. He's very free-form. And I do admire that."

Hudson noted, "He would just wade down the street, like he was the mayor. We all knew that there could be a bunch of crazies out there, but if there were crazies out there, Bill Murray never seemed to notice."

And with the Ghostbusters shoot the talk of the town, Reitman said, "If we started a scene with 100 extras that we had hired, two hours later there would be 400 people on the scene, people just showing up."

17. New Yorkers didn't even seem put out by Central Park West being closed off for the Ghostbusters' police-escorted drive down the street toward Dana's building to prevent mass hysteria.

"There's something about them that made it very different from the usual welcome of the film in New York," Weaver said, "which is, 'Oh Christ, here's another movie blocking my neighborhood.' There was none of that."

18. Joining the ranks of iconic as-seen-onscreen Manhattan residences like The Dakota, Dana's Art Deco apartment building was played by 55 Central Park West, a 19-floor co-op built in 1929.

For the record, the architect wasn't Gozer worshipper Ivo Shandor, but rather the firm Schwartz & Gross.

19. When the other terror dog goes after Louis, it chases him to landmark NYC restaurant Tavern on the Green, at 67th Street and Central Park West.

Where no one was bothered by the hysterical man outside screaming and pounding the glass to get in.

20. So be good, for goodness sake, whoa, the scene where the Ghostbusters are briefly in jail was shot at an "actual New York prison facility, now out of commission and essentially abandoned," according to Don Shay's Making Ghostbusters. 

But the crew may not have been alone.

"Dan Aykroyd said, when we were shooting there, 'If there are ghosts anywhere, they would be here,'" Medjuck recalled to Shay. "And he was right—it had a very eerie feeling to it. Later, we discovered scratches in the film that was shot that day, and were were all afraid we'd have to go back there to redo the scene. Fortunately, [editor Sheldon] Kahn was able to work around the scratches in editing and the reshoot wasn't necessary."

21. The pole still works at the iconic Beaux-Arts firehouse that served as Ghostbusters headquarters, which is actually the home of Firehouse, Hook & Ladder Company 8.

So, the not-condemned site at 14 North Moore Street in Tribeca remains a popular pilgrimage destination. And if that address sounds eerily familiar, the loft John F. Kennedy Jr. and Carolyn Bessette Kennedy shared was at 20 North Moore.

22. William Atherton, who played the Ghostbusters' chief human nemesis, EPA inspector Walter Peck, wore the same suit in all of his scenes.

"Bureaucracy 101, that's my tone," the veteran character actor who was, indeed, called "D--kless" on the street for years afterward, told EW. "He's everybody at customs or an airport that's made your life hell."

Grotesquely stupid or not, that sort of fellow knows how to play the game, and that's Mayor Peck to you in Ghostbusters: Frozen Empire.

23. The 1959 Cadillac Miller-Meteor Sentinel that Ray finds to be the company vehicle needed some work (the original repair estimate was hiked to $4,800 to reflect inflation in 1983), but soon enough the converted hearse-ambulance was handily getting them everywhere they need to go.

The tricked-out Ecto-1 was the same kind of car, but the inky-colored relic Ray first shows up in was returned to its owner intact.

24. Ray Parker Jr.'s iconic "Ghostbusters" theme was a No. 1 hit but did not win Best Original Song at the 1985 Oscars, though only because that may have been one of the most stacked years ever.

The competition included the titular Kenny Loggins-sung theme and Deniece Williams' "Let's Hear It for the Boy" from Footloose, Phil Collins' titular "Against All Odds (Take a Look at Me Now)" and the eventual winner, Stevie Wonders' "I Just Called to Say I Love You" from A Woman in Red. 

25. Aykroyd created blobby green ghoul Slimer as an affectionate tribute to Belushi's Animal House character Bluto, who much like the late actor himself had a zest for food and mischief.

26. What left Venkman feeling so funky after being slimed was a "disgusting combination of corn syrup, starch, and some sort of an adhesive," Murray cracked on TODAY in 2014, "and a kind of a poison that's used on chinch bugs."

27. Reitman thought of Bond girl Grace Jones to play Gozer, but in the end they went with model Slavitz Jovan. Aside from her red eyes, she wouldn't have looked out of place at a downtown club in her skintight bodysuit (that she needed to be sewn into) and high-heeled boots. 

Jovan couldn't see through her painted contact lenses, however, so it was "kind of a challenge" even to just stand in the right place, she told EW. "And then I'm kind of flying up in the air and then landing on a rock or something, so I was a little bit scared."

28. The 100-foot Stay Puft Marshmallow Man that stomps through the streets was dreamed up by Aykroyd and given form by his college roommate John Deveikis.

"I said, 'Give me a brand symbol that kind of looks like the Michelin Man and the Pillsbury Dough Boy—mix 'em,'" Aykroyd recalled. "He comes up with the sailor, which was brilliant." (Alas, they didn't have the effects capability to have him rise from the Hudson River, as the script called for, in the amount of time available.)

29. When crossing the streams works and the creature explodes, shaving cream rained down upon the city, drenching some more (Aykroyd) than others (Murray purposely wanted to have hardly any on him).

"I remember being on set the day when William Atherton got nailed with all marshmallow," Jason Reitman, who took the torch from his dad to direct 2021's Ghostbusters: Afterlife, told Empire. "They emptied a giant garbage bag filled with shaving cream. I kept this little white piece of foam, a piece of dead Marshmallow Man, for years after in my bedroom."

30. Now we'll tell you about the Twinkie.

After Ramis died in 2014, in honor of Egon's treatise on how much pyschokinetic energy was building up in the New York area, "there was like an altar of Twinkies and letters and pictures and flowers and candles at the Manhattan firehouse where they filmed the movie," his daughter Violet Stiel told EW. "It was really nice."

And much better than leaving spores, molds and fungus.