This post contains spoilers from Sunday's Mad Men half-season finale.

Mad Men danced its way into its mid-season finale Sunday night with the passing of Bert Cooper, SC&P's beloved father figure. A late Cooper appeared to Don Draper in the final moments of the episode as a hallucination, soft-shoeing (or was it soft-socking?) to "The Best Things in Life Are Free."

It was a curious musical interjection during an episode revolving around safe landings — landing on the moon, landing the Burger Chef account and landing planes.

But the song is less of a head-scratcher when remembering that Cooper was played by Robert Morse, a Tony-award winning actor (for his role in How to Succeed in Business Without Really Trying). It was a brilliant hat tip from show creator Matthew Weiner to the actor for his years of advertising service.

Within minutes of the dance number, Bert Cooper and Robert Morse began trending on Twitter, proving that we love Bert, to the moon and back.

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