

1. Stay determined. Psych's big Clue episode was originally planned for Season 6. "We had written it around Tim Curry's character from "The American Duos" episode, and Tim Curry had played the butler in the movie, and we had planned on him. And then Tim wasn't available when we were shooting it, so we ended up pushing the episode to this year," Franks says. "And then he wasn't available for our second time, so we said, 'All right. We're going to move on with the story.' We waited one year for him, but we weren't willing to wait two."

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2. Be adaptable. Once Franks and the writers knew that the episode couldn't be centered on Curry's character, the question became, who would the dinner party be centered on? "We had this story of a rock star, and we never found a way to put it into an episode, or it was always incomplete," Franks says. "We said, 'Why don't we go back to the rock star,' who is writing his memoirs and inadvertently becomes a suspect in a murder that he doesn't quite remember because of his lost, hazy years of debauchery. It was great that we had that already developed there, and it made the most sense for this house and the group of people that show up."

3. Know when to mix it up. Although the episode will feature three of the original film's stars — who Franks says shared "very fond memories" of working on the original — Garrett Morris and Tears for Fears' Curt Smith also pop up. "There were too many great people up there at the same time. The fact that we got them all here at the same moment doesn't work out for us usually, because it's hard to get people to go up to Canada, especially when it's cold. But one by one, they started falling into place," Franks says. "All the other writers got very jealous for their episodes when they saw their guest cast compared to this one."

Sccop: Psych to let fans vote for the ending of 100th episode

4. Let everyone in on the fun. Unlike some of the show's past tribute episodes, Franks says fans won't have to have seen Clue the movie to appreciate the episode. "The movie didn't make much money at all when it was first out. People only discovered it on VHS and DVD beyond that, and you can pull a lot references in that not a lot of people will understand," Franks says. "So we were more thinking in the style of the board game, and then doing our winking nods to the movie itself. You could've never heard of the Clue movie and still enjoy it as much as someone who is a huge fan of that movie."

5. Get the viewers involved. Just like the original film, "100 Clues" will have three different possible endings. But unlike the original, which was shown in theaters with one randomly selected ending and then released on VHS with all three, viewers will get to choose the ending based on who they think committed the crime. "We always were saying this is a difficulty 9.9 for our episodes, because they all had to make sense, and all the characters had to be legitimate suspects for the majority of the story," Franks says. "It all had to make sense in many ways, and oftentimes our head hurts. But it was one of the first things we broke last year, and that way we had time to tweak and turn it around and play with it." Fans on both coasts will be able to vote for suspects online at Psych's official website, and also by tweeting using specially designed hashtags for each suspect:  #PsychButlerDDit, #PsychGroupieDDit, #PsychManagerDDit, #PsychAuthorDDit and #PsychHostDDit.

6. Know your audience. One alternate ending that viewers won't see is the one that paints Shawn as the (accidental) culprit. "Somehow Shawn had accidentally caused the death to take place," Franks says. "It was really funny besides the fact that Shawn actually caused an innocent person to be killed." However, the idea was scrapped when Franks and the writers realized everyone would vote for Shawn's ending. "We had to take that one off the table, but it was our favorite idea going in," he says. "We've actually wanted to do that since the beginning of the show — finding out the killer is one of our cast."

Psych airs Wednesdays at 10/9c on USA. Don't forget to vote for the killer online at Psych's official website, and on Twitter.