Nicole Richie's big action scene on Chuck is going to be a wet one!The socialite, who "kicked ass" during her stint on the NBC show, will battle secretive operative Sarah (Yvonne Strahovski) in a shower, creator and producer Josh Schwartz reveals."The premise of the episode is Sarah has to go back to her high school reunion where she was not so popular and not nearly as beautiful," he tells OK! at a TCA conference. But the reunion is not all fun and games. Sarah and Chuck (Zachary Levi) are there on a mission -- tailing Nicole's character, a mean girl who "tortured" Sarah back in the day."While there, things go awry," Josh teases. "The old high school shower becomes the location of a seriously wet showdown."Nicole won't be the only familiar face in the episode -- Boy Meets World's Ben Savage also appears as Nicole's husband.And the gushing won't stop for Nicole's performance. "Nicole came guns blazing," Zach tells OK!. "She was ready, she was prepared, and she had a good time."