In the dead of a winter’s night in an abandoned building in Winnetka, 20 miles north of Chicago, a man named Michael Guido, wearing a trench coat and fedora, suddenly found himself having a tense exchange with an older man pointing a gun at him:

“I’m gonna give you to the count of ten to get your ugly, yellow, no-good keister off my property before I pump your guts full of lead.”

“All right, Johnny, I’m sorry,” Guido replied, backing away. “I’m going.”

“One. Two. Ten!”

As far as beloved family Christmas movies go, Angels with Filthy Souls is an unlikely one: a gritty, noirish gangster flick in which a crow-voiced curmudgeon abruptly unleashes a blaze of gunfire on his unsuspecting victim.

Even more unlikely, since it doesn’t exist. Angels with Filthy Souls is the fictitious gangster movie tucked into the beloved John Hughes and Chris Columbus family comedy Home Alone, which turns 25 this year. It’s the forbidden flick nine-year-old Kevin McCallister at last indulges in while enjoying a tremendous helping of ice cream—“Guys, I’m eating junk and watching rubbish! You better come out and stop me!”—only to be horrified by what unfolds. Later, he uses it as a weapon in his arsenal against the Wet Bandits (and a hapless Little Nero’s Pizza delivery boy).

Reeking of authenticity, Angels with Filthy Souls is not just a uniquely persuasive parody. It’s the perfect movie-within-a-movie: a one minute-and-20 second noir-in-a-nutshell that feels like a fleeting glimpse of a long lost classic. Its dialogue is crisp, the characters and performances credible, the rapid escalation of its drama enthralling. Plus it culminates in not just the most memorable utterance in Home Alone but one of the great movie lines of all time: “Keep the change, ya filthy animal”—the sardonic invitation since emblazoned on many a Christmas sweater.

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