Neon-pink clouds resembling scenes from Stranger Things were spotted looming over a Kent district.
Residents across Thanet photographed the luminous colours lighting up the area last night - prompting many to compare the images to the "upside down" in the hit Netflix series.
The images sparked a massive reaction on Facebook, with some locals even quipping they should call Ghostbusters.
Michelle Garrett snapped a picture of the "very eerie sky" from her window in Birchington, after her eight-year-old daughter told her: "Mum, the sky is on fire."
The sales assistant, 44, said: "It was amazing, very spooky.
"I thought it was just a reflection coming from Halloween lights."
Reacting to a photo of the sky online, commenter Chloe Keenan asked: "What in the Stranger Things is that?"
Those living in the area also joked the glowing sky could be signalling the arrival of the programme's villain, Vecna.
Meanwhile, others quipped they were "in the upside down".
Much of the science-fiction programme takes place in an alternate dimension called the "upside down", which has a glowing red sky.
Ricardo White also saw the pink glow as he drove along the A299 Thanet Way in Ramsgate.
"I was leaving my partner's house at about 11pm and I noticed that the sky on the horizon was a bright-pink colour," the 44-year-old housing officer told KentOnline.
"I have never seen nor experienced this before - normally the sky is an orange colour.
"I did not know what to think."
It is understood the luminous sky was caused by lights shining at Thanet Earth, a large-scale greenhouse-farm in Barrow Man Road, Birchington.
The firm says "escaping light" from the facility can create "a spooky, glowing landmark" on nights with low cloud cover.
"We do everything we can to minimise this," Thanet Earth added.
Facebook user Zoe Foulis explained the glow occurred because "when it's a certain type of cloud it holds the light and spreads".