RELATED STORIES Matt's Inside Line: Scoop on The Boys, TWD, Lucifer, Supernatural, NCIS: LA, Manifest, SEAL Team, NCIS and More!

Matt's Inside Line: Scoop on The Boys, TWD, Lucifer, Supernatural, NCIS: LA, Manifest, SEAL Team, NCIS and More! Lucifer's Final-Season Episode Count Revealed -- And It May Surprise You

The Devil went down to… Earth-666, when Lucifer Morningstar popped up during Part 3 of the Arrowverse‘s “Crisis on Infinite Earths” crossover event. To those who were legit surprised on Tuesday night, the cameo was one Hell of a fun moment, as Legends of Tomorrow‘s John Constantine asked his old friend for a favor to help Arrow‘s John Diggle and Mia Smoak-Queen make a freshly resurrected Oliver Queen as right as rain.

Some Arrowverse fans, however, had gotten wind of the unexpected crossover cameo when a Vancouver-based “autograph hound” spotted Lucifer star Tom Ellis filming with Matt Ryan, David Ramsey and Katherine McNamara — and then decided to spoil the sighting for reasons.

Ellis was at the time asked about taking part in the “Crisis,” but unlike Lucifer himself, he lied about why he was seen in VanCity (by claiming he was there “to visit my friend for his birthday”).

“OK, I’m sorry I fibbed about being in #CrisisOnInfinteEarths!” the actor said on Twitter after his cameo aired. “We were desperately trying to keep it a surprise, but then unfortunately some paparazzi spoiled [it]. So [the denial] was a mild attempt to put the genie back in the bottle.”

Lucifer co-showrunner Joe Henderson apparently made the trip to Vancouver with Ellis, to oversee the Arrowverse’s handling of his antihero. “Hope everyone enjoyed the #Lucifer surprise in Crisis,” Henderson said on Twitter. “Big thanks to [Arrowverse EP] Marc Guggenheim for making it happen, [Flash showrunner] Eric Wallace for making us feel so welcome on his set, and Sterling Gates and Lauren Certo for writing a great Lucifer!”

Henderson then explained how Lucifer’s appearance — on Earth-666, where he is running LUX and not back lording over Hell (while juggling multiple lovelies) — fits into the Fox-turned-Netflix series’ continuity.

“For #Lucifans wondering, the Crisis cameo is a prequel to our show,” he said. “In the script, Lucifer says he’s expecting [onetime LUX employee] Delilah in the alley. They had to cut the line for time, but I thought that was a clever way to ground the ‘when’ of it all.”

Within said Lucifer Easter egg (watch the full scene below) laid a far more subtle one, as spied in the bottom-right corner of the LUX flyover: a billboard for HBO’s Watchmen, which also started out as a DC comic:

Finally. Someone noticed. Special thanks to Damon Lindelof for making this one happen. https://t.co/i97GkvxOfR — Marc Guggenheim (@mguggenheim) December 11, 2019