A show of love for Nick Offerman and Megan Mullally

Nick Offerman races into the lobby of West Los Angeles' Odyssey Theatre, pulls off his green trucker's cap and wipes his brow. Megan Mullally, right behind him, smooths her magenta-tinted hair and adjusts her cat-eye glasses.

"It's a thing with us," Offerman says, only slightly abashed for arriving 30 minutes after rehearsal was set to begin for their new play "Annapurna." "We're chronically late."

Mullally slips her arm through Offerman's, he pecks her cheek and they exhale in tandem.

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The gesture is so in sync they burst into laughter as if under the spell of some kind of loopy love dust.

"We just like each other," Mullally says with a girlie giggle.

Most people know Mullally and Offerman from their well-known sitcom characters — she played the shrill and self-obsessed Karen Walker on "Will & Grace"; he's the cranky and carnivorous Ron Swanson on "Parks and Recreation."

They are also one of Hollywood's most enduring couples. Married nearly 10 years, they've been together 13 years and constantly find ways to work together. Offerman appeared as a plumber on "Will & Grace"; Mullally shows up on "Parks" as Ron's ex-wife, the hot and evil Tammy II.

On Adult Swim's "Childrens Hospital," he's Det. Briggs to her Chief. And they're the voices behind the hippie-farmer couple on Fox's animated "Bob's Burgers."

This spring, they're in the indie film "Somebody Up There Likes Me," which Offerman produced. They just finished shooting "Townies," starring Seth Rogen and Zac Efron. And on May 31, they'll appear in "The Kings of Summer," Jordan Vogt-Roberts' coming-of-age comedy, which opened at Sundance with the title "Toy's House."

Right now, they are starring in Sharr White's "Annapurna," directed by Bart DeLorenzo, their longtime friend, collaborator and founding artistic director of the Evidence Room.

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The two-person play, which will be at the Odyssey through June 9, is a languid, emotionally suspenseful love story about an overdue reckoning between two deeply entwined people, Emma and Ulysses, who haven't seen each other in 20 years. Set in the Colorado mountains within the confines of a dilapidated trailer, it's more a drama than a comedy, exploring love, addiction, the constructs of family and impending death. Yet as the story unfolds, it's studded with funny and poignant moments.

"These are hard parts to cast," DeLorenzo says. "You need terrific comedic actors who can also bring enormous depth, which is rare. Megan and Nick, they bring the depth of their relationship to it. They spark different reactions in each other, they inspire each other; and I knew that would add a whole other layer to the production."

During rehearsal, there's an almost visible electricity as their characters spar.

In the scene, which DeLorenzo calls "a really dark moment in these characters' lives," Emma reveals a terrible truth from their past. It couldn't be further from Mullally and Offerman's real life; but the depth of connection and intimacy rings true and is especially potent in the 99-seat theater, where even the back row feels as if it's in the on-stage mobile home.

"I can't write something about me, without it being about you!" Offerman's character, a poet, says at one point.

"Nice, nice, very nice," DeLorenzo says. Offerman walks to the edge of the stage for more notes, an intense, pensive look on his face.

Mullally, meanwhile, does an exaggerated chicken-dance across the stage — something of a reverse moonwalk, with her neck jutting out — to blow off steam. Offerman cracks up.

"It's a lot of alone time together," Mullally says later in the green room about having no other cast members. "It's great. There are no annoying others."