Residents of Arbroath and Montrose were baffled by a pair of blueish-purple lights floating in the night sky.
The lights, which were seen by residents between 9 and 10pm on Tuesday, appeared to float through the clouds, occasionally disappearing before coming back.
Those who spotted them were quick to make light of the situation, comparing the scene to E.T and Batman’s Bat-Signal.
However others were more confused by the strange orbs and questioned paranormal activities.
One St Vigeans resident said: “I really started to think this was a UFO or some experimental weapon being tested.
“I saw it near the boundary with RM Condor about 9.30pm.
“At first there seemed to be a beam connecting the two patches of light but that soon disappeared.”
He added: “All that was left was two patches of violet light.
“The patches were light squares with the edges rounded and there looked to be a little gap between the two objects.
“Both moved fairly slowly and a couple of times disappeared completely before flashing back on.
“They moved further over St Vigeans and then disappeared.
“It was not an alarming experience, just a curious one.
“Although the patches appear blue on the photograph, in reality, they were more a violet purple.”
What were the lights?
While it may sound like science-fiction, it’s the violet visions had a simple explanation.
Network Rail say the blue lights were the result of their measurement train which uses lights on its roof to scan overhead power lines.
The locomotive runs up and down the east coast, using its many cameras and sensors to asses the track, signalling and overhead power.
When mixed with low cloud cover, the train’s lights create an effect identical to what was seen on Tuesday night.
A spokesman for Network Rail said: “Our measurement trains plays a vital role in maintaining the railway – helping us to spot potential faults before they affect services.
“The lights seen in the sky are caused by a monitoring system which is used to check overhead power cables and other structures above the height of the train.”