An observatory in a small New Mexico town has been forced to close amid very suspicious circumstances.
The National Solar Observatory in Sunspot was closed a week ago, as was the town’s post office, for reasons reported to be security-related.
The local sheriff’s office is in the dark as much as anyone, with Otero County Sheriff Benny House telling ABC 7: "The FBI is refusing to tell us what’s going on.
"We’ve got people up there (at Sunspot) that requested us to standby while they evacuate it, nobody would really elaborate on any of the circumstances as to why.
"The FBI were up there. What their purpose was nobody will say."
He added: "For the FBI to get involved that quick and be so secretive about it, there was a lot of stuff going on up there.
"There was a Blackhawk helicopter, a bunch of people around antennas and work crews on towers but nobody would tell us anything."
The observatory’s website said: "We apologise for any inconvenience this may cause you, however, due to unforeseen circumstances, the Sunspot Solar Observatory, including the site, is temporarily closed, until further notice."
The observatory is managed by the Association of Universities for Research in Astronomy and if spokeswoman Shari Lifson knew anything, she certainly wasn’t sharing it.
She told the Alamogordo Daily News that the group was "addressing a security issue at this time".
"We have decided to vacate the facility at this time as precautionary measure.
"It was our decision to evacuate the facility."
She could not say when normal operations would resume but, according to ABC 7, the post office cannot be re-opened until law enforcement officials say so.
Rod Sturgeon for the US Postal Service said: "We were told on 6 September that we would be evacuated along with the surrounding area, we were not told why, we were told just to be out of the area.
"We remain suspended until we are allowed to return."
A number of news outlets attempted to get some answers from the FBI but there were no replies.
Conspiracy theorists have their own ideas, with Reddit abuzz with possibilities ranging from the FBI having uncovered an illegal operation, being the front group for a secret taskforce to "maybe they saw something in the sky".
Other ideas given by armchair experts include mercury contamination, anthrax in the mail or China spying, the latter two described by their author as "the simplest answers".
(c) Sky News 2018: Mystery closure of observatory and FBI presence in Sunspot, New Mexico