The fifth season of “Mad Men’’ ended majestically Sunday night with Don Draper, planted at an elegant bar, approached by a beautiful woman who inquired, “Are you alone?’’

On the soundtrack, Nancy Sinatra trilled the theme from the 1967 James Bond film, “You Only Live Twice.’’ And Draper, more handsome in that moment than any James Bond could be, struck a heroic pose before the show cut to black until next season.

Of course, he’s alone!

Then, within moments, the song (with its yearning, sexy lyrics, “You only live twice … one life for yourself and one for your dreams’’) was trending on Twitter.

Note: Further spoilers from the finale await.

Season Five of the AMC drama had begun on Memorial Day 1966, roughly seven months after last season’s conclusion.

The season’s breakout character was Megan, the ooh-lah-lah secretary Don married somewhere in between. She channeled the glamour of Jackie Kennedy by way of the emerging `60s style of a Jean Shrimpton. On top of that, she proved smart, quickly showing her stuff as a creative force at Don’s ad agency before resigning to become a full-time struggling actress.

Even while displaying commitment to Don and their marriage, she displayed an independent streak that threatened and puzzled him all season.

Puzzled her, too. In a drunken funk in the finale, she told Don his refusal to support her career was either because he wants her waiting for him at home each night, or he believes that, as an actress, “I’m terrible. But how the hell would you know?’’

By the end of the episode, Don (series star Jon Hamm) had come through for her. He recommended her for a commercial. But he did it with a mixture of pride and foreboding.

The Sterling Cooper Draper Pryce agency was prospering as the season concluded — but not in ways that gratified Don.