Factual error: The bad guys are supposedly auctioning off the stolen Mona Lisa. But they and their prospective buyers aren't very art savvy. The painting is more than twice the size of Da Vinci's actual masterpiece. (00:44:50)
Visible crew/equipment: When the old lady enters the costume shop to retrieve her knitting book, an equipment shadow sweeps across the lower right of the screen, then moves back to the left. (00:11:45)
Continuity mistake: Steed tosses his opponent over his shoulder during the scuffle. The man lands on his back with his right hand extended over his head. But when the shot cuts to a different angle, both his arms are instantly down at his sides instead. (00:38:25)
Continuity mistake: Mrs. Peel is nibbling at a bunch of grapes. Every time the shot cuts to full, there are more grapes on the stem than in the close-ups. (00:35:30)
Continuity mistake: Georgie's wig, which she'd pulled off and placed over the flowers on the mirrored stand, either changes position or disappears altogether during Steed's fight with Ivanov. (00:40:55)
