Fire in the sky? Alien takeover? Just plain weird science?
Either way, an eerie yellow glow made for some spectacular, technicolour skies above Toronto Friday night.
The glow seemed to be emanating from BMO Field, but the colours could be seen across the city as patches of fog hung above it.
A Maple Leaf Sports and Entertainment (MLSE) representative couldn't confirm the field was the cause of the glow.
But she said grow-lights meant to mimic the sun are used year-round to stimulate the grass in the stadium to grow faster and help get the pitch into shape ahead of the season for Toronto FC of Major League Soccer.
Whatever the cause, Toronto's sky looked to be ablaze.
Giant fire on Lake Ontario or what? pic.twitter.com/6aH0drJcul— @seanandernacht