Amid a sea of baggy shows that don't quite know what they're doing and are taking too long to do it, FXX's Man Seeking Woman stands out for its focus and speed. Simon Rich's surrealist comedy — about a 20-something Everyman named Josh (Jay Baruchel) looking for love — starts its third season Jan. 4, and it continues to be an admirably tight show. A series built around taking a figurative expression and making it literal has every reason in the world to get messy: What if your ex's new partner was actually Hitler? Suppose you go to a sex shop and your partner chooses "The Kyle," an Australian beefcake in a life-sized Ken box? Whole movies could be written around these premises, but in Man Seeking Woman, they constitute just one of the three ruthlessly disciplined acts that make up a single 20-minute episode. "I always try to make things as economical as possible," Rich has said. "I always try to make the turn sudden. I try not to shift a scene gradually, I try to shift a scene dramatically." And it usually works.

This new season, Man Seeking Woman pivoted suddenly indeed: If its first season could be paraphrased as "Man Misses Woman" and its second as "Man Seeks Woman," its third is "Man Finds Woman." But there's a caveat: A character who's never been introduced before takes up so much screentime that the series could just as easily be called "Woman Gets Man." Josh has a girlfriend. Her name is Lucy, she's played by Katie Findlay, and she has seized center stage.

That could be a worrying departure for a show whose elevator pitch was dudes and singledom. But the series doesn't hesitate and grants the very character who undoes its premise unprecedented centrality. What happens, Rich wonders, when Josh the Everyman is coupled off? The surprising answer is that the show's delightful metaphors start expressing her insecurities and anxieties as much as his. And it's as good as ever. Maybe even better: "Futon" and "Popcorn" are arguably two of the series' best episodes.

If "Man Finds Woman" sounds like a dull sitcom premise, it should: Love is a notorious comedy-killer. Up until now, Man Seeking Woman dramatized universal scenarios by trying them out on poor Josh, whose only consistent traits are that he's an underachiever yearning for companionship. Baruchel plays him as the straight man, the cipher, the guy who walks into a bar, and there's an invisible virtuosity to that performance: "He's just unbelievably naturalistic regardless of how insane our premises are," Rich says of Baruchel. "He always keeps things emotionally grounded and has an unbelievable ability to play things truthfully no matter how insane they become."

This is both true and, in its own way, limiting: How many episodes can you write around a random man's difficulties before the character blossoms into specificity and stops being random? How long, as an actor, can you remain that generically responsive, that strategically diffuse? My early thoughts on Man Seeking Woman were: This is good, but it can't go on for long.

The show's solution this season was to bring in Lucy, who — compared with Josh's haziness — is more vividly rendered, more sharply delineated. She's both too pretty and too nervy to constitute a blank Everywoman to Josh's Everyman. She chooses her Skype and Facetime backdrops carefully, and a sequence in which she opts to murder a friend who's seen her messy apartment nails a particular kind of impulse to impress. A graphic designer with a good eye, she's also kind of an immature mess, with a very particular set of coping fantasies.

What that means is that the show's playful and unhinged conceits — the delightful animated metaphors that channel Josh's anxieties and make this show what it is — gently expand to include Lucy's subconscious neuroses too. Whole episodes of season 3 revolve around Lucy's issues from Lucy's perspective without seeming to notice. If season 3 is about Josh in love, the shifts he's experiencing as he makes room for Lucy in his life are magnified by the extent to which the series includes her.

One episode begins with a normal enough premise: Josh and Lucy go visit her parents. But things go off-kilter quickly: Lucy is on high alert for parental passive-aggression. Josh doesn't see it. An amazingly effective paranormal activity detection parody gives way in the second act to a House of Un-American Activities satire in which Lucy tries Josh for being a "parental sympathizer." (That both protagonists are fully vested in the fantasy trial illustrates how committed the show is to their couplehood.) But the third act belongs to Lucy alone. She ends up in an exquisite Narnia-meets-Where the Wild Things Are Neverland filled with the friendly monsters of her childhood. They've grown up and think her parents have a point. One explains an IRA to her. Lucy and Josh works things out, and by the end of the episode neither Lucy nor Josh are present: The monsters have taken over.

That the show has drifted this far from Josh actually makes the comedy better. In its first few episodes, Man Seeking Woman's comedic problem was that it so closely aligned its jokes with Josh's point of view that everyone around him became caricatures to the precise extent that he saw them as being complicit in his misery. The premise didn't have much room to grow. The show got sharper and funnier the more it decentered Josh's frame of reference and gave the premise room to breathe.

Lucy gives Man Seeking Woman more opportunities to expand and develop the show's amazing sensibility. The sad sack storylines had run out. Lucy doesn't just offer some new plots; her inclusion indexes how much the show has grown into its experiments, and learned to trust that the shenanigans will ripen into something better than a punchline given space enough and time. It's no small achievement to maintain the show's taut three-act structure, its sly use of metaphor, and overall tone — all while introducing a whole new character, writing her a different but equally surreal sensibility, and upending the show's basic premise. But Man Seeking Woman pulls it off. Josh and Lucy are one of television's most enjoyably watchable couples.