The Beatles were one of the first popular bands to turn their album covers into works of art, so it’s natural that in addition to clues in the music their fans would scour album covers as well. And they found tons of hints that Paul McCartney was long dead and being impersonated by a lookalike.

First there’s the cover of “Sgt. Pepper’s Lonely Hearts Club Band,” the first album recorded by the group after McCartney’s “death.” As noted by Live Science, fans were struck by the funeral-like imagery, and on the back cover, McCartney is photographed with his back to the camera, while wearing an “O.P.D.” patch that supposedly means “Officially Pronounced Dead” (it’s actually an Ontario Provincial Police patch).

Then there’s “Abbey Road,” the last album The Beatles recorded. As Rolling Stone notes, the album’s famous photo of the band crossing the street can be interpreted as a symbolic funeral: John Lennon is the preacher dressed in white, McCartney is in a suit and has bare feet because that’s how dead bodies are buried, George Harrison is the gravedigger in denim, and Ringo Starr is the undertaker in black. Also, McCartney has a cigarette in his right hand, but he’s left-handed, the license plate on the car parked nearby reads “28IF,” and McCartney would have been 28 if he hadn’t died. There’s more — and other album covers were similarly believed to contain tons of cryptic clues.

The “Paul is Dead” theory has been around for so long it seems like settled history, but in 1969 when it first emerged it was a legitimate fad for a while. And as reported by Rolling Stone, like all fads it inspired a lot of quickie attempts to cash in, including several novelty songs written and recorded incredibly quickly.

Most were thrown together by music industry professionals who were skilled in writing and recording songs quickly, like Lenny Capello and Rocky Saxon, who released “Brother Paul” as Billy Shears and the All-Americans (authorMichael J. Hockinson notes they wrote the song after a radio station hired them to write it as theme music for its coverage of the rumor), or Zack Van Arsdale, who released “We’re All Paul Bearers” as Zacherias & The Tree People.

But one of these novelty songs was actually recorded by a legitimate music star. “So Long, Paul” was released under the name Werbley Finster but was actually written and recorded by José Feliciano, who had the good sense to hide behind a pseudonym. Terry Knight, who never quite broke through to true fame but who was well-known as a musician and DJ in the 1960s, threw caution to the wind, however, and released “Saint Paul” under his own name. The weirdest part is that some of these songs were actually pretty good.

Just in case the whole “Paul is Dead” theory — which involves covering up the death of one of the most famous people of all time and then placing elaborate, mysterious clues to the event in songs and images for years afterward — doesn’t seem elaborate enough, there’s also the presence of an impostor.

One of the main problems with believing Paul McCartney died in late 1966 is the fact that a very-much alive McCartney has been wandering around for the ensuing 50-plus years. According to Far Out Magazine, fans explained this very simply: The Beatles hired a man named William Campbell to impersonate McCartney. Campbell was supposedly a Canadian musician who had won a Paul McCartney look-alike contest. Radio X notes that some versions of the story had Campbell undergoing some plastic surgery to make him look even more like McCartney, pointing to some scarring on McCartney’s face that wasn’t there before 1967 (McCartney had been involved in a motorbike accident that had left him scarred).

This is all bolstered by the fact that at the end of the first song on “Sgt. Pepper’s Lonely Heart’s Club Band” (the first album recorded after McCartney’s “death”), the band sings “So let me introduce to you / The one and only Billy Shears!” It’s supposedly a sly nod to Campbell joining the band — some even went so far as to suggest Campbell’s middle name was Shears.

You might think that Paul McCartney’s continued existence and extreme productivity — he’s released dozens of albums as a solo artist or member of a band since 1967 — would have killed this theory. But it continues to stumble along and is still very much alive. In 2010, a documentary called “Paul Really is Dead” was released. And in 2020, Image Comics released “Paul is Dead,” a comic book based on the theory. And filmmaker George Moore released a short comedy film based on the bizarre fan theory in 2018.

Interestingly, scientists continue to kick the tires and try to prove or disprove the theory. As noted by Plastic Macca, in 2009 Italian Wired published an article detailing the efforts of forensic scientists who claimed to have “proved” that McCartney had been replaced in 1966. According to Huge Questions, the scientists initially aimed to put the theory to rest for once and for all but were surprised when their methods actually confirmed it instead. They conducted a “biometrical” analysis of McCartney’s face in photos and video over the years and concluded that there were changes and discrepancies that couldn’t be explained via natural aging or other factors.

For example, they noticed that the curve of McCartney’s jaw changed after 1967, as well as changed shadowing on his face that might be explained by plastic surgery of some sort, which McCartney would have been unlikely to have undergone in his late 20s.

By 1977 the whole “Paul is Dead” rumor had faded into the background noise of the universe. But there was one last gasp.

As Louder reports, in August of 1976 the band Klaatu released an album called, mysteriously enough, “3:47 EST.” What made the release interesting was a complete lack of information about the band. No one knew who was in it, where they’d come from — or anything, really. The album received some very good reviews, but it didn’t make much of a splash, due in part to the dearth of promotion or information about it.

As reported by The Washington Post the story takes a swerve almost a year later, when a rumor started that Klaatu was actually The Beatles, secretly reformed but trying to avoid the media firestorm such an announcement would make. Sales surged, and people began analyzing the music, which did in fact sound like something The Beatles (or a group of musicians heavily influenced by them) would have made.

Then, as Vulture notes, things got even more dense when that theory tied back into the Paul is Dead theory as people speculated that instead of The Beatles getting back together, the Klaatu album was actually an album the band had recorded in 1966. The master tapes had been lost, and when they were finally rediscovered the band decided to release it as a tribute to their dead bandmate Paul.