'American Housewife' Sneak Peek: Katy Mixon Crashes Nathan Fillion's 'Firefly' Party (Exclusive)

It's off to the fan convention! ET exclusively debuts a first look from Wednesday's episode.

American Housewife Firefly = the crossover you never thought you needed!

On Wednesday's episode of the ABC comedy, titled "Finding Fillion," Katie (Katy Mixon) and her children, Taylor (Meg Donnelly) and Oliver (Daniel DiMaggio), set out to find Firefly icon Nathan Fillion at a New York City fan convention in order to impress the other moms at school and invite him to attend the school's spring gala.

It looks like Katie's mission to find Fillion is going to come up short, as she and her daughter argue over prom dresses in an area of the convention that looks eerily similar to a pilot's command room on a Firefly-style ship.

"Hey, nerd, I'm trying to have a private conversation here!" Katie yells angrily, causing Fillion -- rocking his signature Firefly browncoat -- to turn around and make his presence known. 

"That's cool, I'm trying to have a private peanut butter and jelly sandwich," Fillion says, causing Katie to gasp and ask him what he's doing there.

"Well, I'm the captain of Serenity," he says, completely in character as Mal Reynolds, "and my tummy was getting rumbly so I got my sammy." But Katie knows this is the only opportunity she'll have to ask Fillion if he could make a little cameo at the school gala. Watch the exclusive sneak peek above to see what happens next.

American Housewife airs Wednesdays at 9:30 p.m. ET/PT on ABC.