Watch: In 1966, 'That Girl' gave us the prequel to Mary Tyler Moore's first Christmas episode

Here's why the 'Mary Tyler Moore Show' special is called "Christmas and the Hard Luck Kid II."

TV viewers likely did a double-take when they picked up their TV Guide in 1970 and saw a listing for The Mary Tyler Moore Show's very first Christmas episode. It was called "Christmas and the Hard Luck Kid II." It was the show's first season. Where was the first installment of this soon-to-be holiday classic? Had they missed something?

It all makes sense with a little TV history lesson. You see, four years before, That Girl had premiered its debut Christmas episode, and it had the exact same name, "Christmas and the Hard Luck Kid." Unfortunately for fans of both, it didn't mean a crossover episode or even a direct sequel in terms of the episodes' plots.

What actually went down is that The Mary Tyler Moore Show co-creator James L. Brooks had been the one to pen both episodes. So, when he went to write Mary Richards' first on-air Christmas, he saw an opportunity to return to the same themes he'd explored with Ann Marie in 1966.

On That Girl, Ann Marie is working as Santa's Little Helper in the mall when her boyfriend Donald comes to visit her. While waiting in line, Donald strikes up an innocent conversation with the woman behind him. It turns out neither of them is there to see Santa, and both are there to see Ann Marie. The woman has brought a gift from her son, who she tells Donald that Ann Marie spent Christmas with three years before.

Her son is not an ex-boyfriend, as Donald clearly suspects, but instead an 8-year-old boy and one of Ann Marie's former students from her days as a teacher at a boarding school. His name is Tommy Phillips (whose voice you'll recognize as Linus from A Charlie Brown Christmas). Tommy's the original Hard Luck Kid, abandoned by his movie star parents whose film is running behind schedule, so they suddenly can't come home to see their son for Christmas.

Ann Marie can't allow the kid to spend Christmas alone, but the school won't let her take Tommy home with her. So she comes up with the perfect Christmas compromise: They'll spend Christmas together in the abandoned school. As Ann Marie does her best to make Tommy's Christmas great, she deals with a streak of bad luck. There's even a literal black cat that crosses her path as she struggles to complete the chores left for her by the caretaker, who she agrees can go be with his family while she takes on his duties.

Here's where things start connecting thematically to The Mary Tyler Moore Show, where Mary Richards agrees to take her coworker's shift and spend her entire Christmas working a long double. Both girls must learn to navigate what it means to be lonely on Christmas.

Since MeTV is airing The Mary Tyler Moore Show's "Christmas and the Hard Luck Kid II" this Sunday, December 17, at 4:30PM EST, as part of our Very Merry MeTV classic holiday lineup, this week is the perfect time to go back and watch That Girl's thematic prequel, the original "Christmas and the Hard Luck Kid." Watch the full episode below.

Want to spent more time with Ann Marie? Watch more That Girl episodes online here.

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