Zachary Levi, Yvonne Strahovski

Nerds and nudity. What more could a fan want from an episode of Chuck?

Star Zachary Levi directed Friday's episode, "Chuck vs. the Hack Off" (8/7c on NBC), in which Chuck (Levi) and his team are trying to track down a possibly devastating computer virus. "It's one of our nerdier episodes," co-executive producer Chris Fedak told reporters at a set visit this month. "There's not as many hack off jokes as you'd think [there would be]. We learn a little about Chuck's backstory, who he was before he met Sarah, a little bit about the hacker side of Chuck."

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And somehow in the midst of this cyber chase, people get naked. "When I first read the script, I was like, 'How the hell am I supposed to do this?'" said Levi, who's directed Chuck twice before. "We've never done this on the show before. I haven't really seen this done on television before. I mean, I have, but it's on [premium cable network shows]. Game of Thrones is not really throwing blur boxes on their stuff, and thank God for that. It was a fun challenge."

Fedak added, "Zach's robe was shorter than Yvonne [Strahovski]'s robe. We were like, 'We made a mistake here.' It was a very short robe."

Elsewhere, in the more clothed portion of the episode, the Buy More hires new employee Vali Chandrasekaren, played by Community's Danny Pudi. "We're big Community fans and we just thought there was a character we were building that only Danny Pudi could do," said Fedak. "And so instead of going, 'Let's reconceive this and make it a different person,' we said, 'let's try and get Danny Pudi to do it.' It ties into the Jeff and Lester story."

Last time we saw Jeff (Scott Krinsky), he had cleaned up his act after receiving doctor's orders to stop sleeping in his car, which had caused his carbon monoxide poisoning. "He's a little bit cleaner and more together, more mentally aware," said Krinsky. "He's got his faculties about him. It's nice to have a little growth to him and to get to do something different with the character in the last season. And the dynamic between Jeff and Lester, that's been a lot of fun to play as well, sort of changing our roles with each other."

In contrast, Lester (Vik Sahay), the other half of Jeffster! was turned in by his former friend and bandmate for attempted murder and was hauled off to jail. "He's been raised poorly, clearly," said Sahay. "He's a desperate, sad, dude who needs love and safety and acceptance very badly, and the only person he got it from was Jeff. And when [the carbon monoxide] got cleared out, Jeff wasn't there for him [anymore]. It created a desperate mania in our boy Lester. He's a broken boy sadly-- kind of why I love him. I feel his insides as I rage out against the world."

It doesn't appear that he stays behind bars for long though, as a scheme is put into motion using Vali. "There is a situation in which they bring in a lesser brown guy to try and mimic the Lester game," Sahay explained. "Maybe it snags me a little, it gets to me a little. ... It's sort of a tactic that's used by certain people in the Buy More to lure me."

Lester may not be too fond of the interloper, but Krinsky felt that Pudi fit right in. "He looks like he's always worked at the Buy More when he you see him in his Nerd Herd costume. It's like, 'Oh God, he's worked here forever.'"

Chuck airs Fridays at 8/7c on NBC.