An iridescent green puddle spotted at a Q train stop on Seventh Avenue in Park Slope Thursday night caused alarm and bewilderment among straphangers.

“Seems fine!” Saahil Desai, an editor at The Atlantic, tweeted from his commute.

Was it a St. Paddy’s Day homage? A toxic leak? The lucky brine that could spawn future generations of teenage mutant ninja turtles? Many took to social media to surmise.

MTA spokesperson Joana Flores was unable to provide any clarity on the leak's original source. She said the liquid appeared to have oozed into the subway station supply room from the street above. No one was injured in the incident and the liquid was promptly cleaned up Thursday evening.

Various neighborhoods in the five boroughs have been home to mysterious pools of neon goop. However, in a prior instance of green subway goop at the 34th Street Herald Square stop back in 2017, it turned out to be water intentionally dyed by the MTA, as a sleuthing tactic used to detect the source of a leak.

Correction: Since publishing this story, the MTA has corrected the location of the mysterious green goo. It was found at the Q station in Park Slope.