Matthew Gray Gubler Matthew Gray Gubler

Like the skilled chess player Dr. Spencer Reid is, Matthew Gray Gubler was thinking ahead when he cut his hair last month (and he didn't do it himself this time).

"Every year, they do these cliff-hangers, so it's like, if you want to change anything, you have to predict it and do it beforehand," the Criminal Minds star tells "[The haircut's] pretty good. I like it. It's summer fun."

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The Season 5 closer is anything but, as the BAU team heads to Los Angeles to trail a serial killer (Tim Curry

) who kills in the dark. In keeping with tradition, the cliff-hanger finale (Wednesday, 9/8c on CBS), which also features Eric Close and Robert Davi, involves not just a case, but the uncertain future of at least one team member. Though Reid, as we learned in Season 2's "The Boogeyman," is afraid of the dark and seems like perfect prey for Curry's Billy Flynn, it's Morgan (Shemar Moore) who's "precariously perched" at season's end. But fans needn't be too concerned, Gubler says."We've had some pretty in-your-face finales. We've had a gun at Hotch's head, we've had exploding cars. This one isn't as insane," he says. "I think it's more of a choice. Maybe I'm wrong, but I don't think you even get the impression that Morgan's going to die. I think it's more like, 'What is Morgan going to do?' We pull a MacGyver cliff-hanger."

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And where is scaredy-cat Reid? "I'm in a dark room that has backup lighting!"Keeping Reid out of harm's way is, of course, the complete opposite of what transpired in the season premiere when the resident genius got shot in the knee to coincide with Gubler's real-life injury (from dancing). That led to reduced screen time and a cry from fans for more Reid in the season's second half. "I think every season they like to showcase different characters. For a few episodes, [my knee] was an issue, but I think, like, Season 2 was a Reid season and this was more of a Hotch [Thomas Gibson] season," Gubler says, adding that Reid has also seen his share of perilous situations over the years. "The writers like to focus on specific characters ... and it's [good for Reid to be] safe in the dark! ... I'm curious to see what Season 6 holds in store."

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One thing's for certain: Curry will be back to conclude his sinister role, which Gubler says is "up there" with such super-unsubs as Tobias Hankel (James Van Der Beek), Frank (Keith Carradine) and The Reaper (C. Thomas Howell)."I think all the unsubs are great. It sort of depends on how much story time they get," he says. "What's the age-old saying? 'There are no small unsubs, only small commercial breaks.' That's the old adage from years ago. He's a good one though. He's definitely top 10."Gubler, who made his directorial debut this season, also hopes to step behind the camera again next year and is considering writing an episode as well. "I totally would write. I've been sort of kicking that idea around a little bit for sure. Maybe if I have some revelations over hiatus, I'll look into that," the 30-year-old New York University film graduate says.

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In the meantime, Gubler will do some different kind of writing — as Moore on Twitter. After filming this week's episode, "The Internet Is Forever," in which a serial killer finds victims on social networking sites, Gibson, Paget Brewster and A.J. Cook joined Twitter. Moore is the sole cast member who is not yet signed up, but that will change soon."I was on, Joe [Mantegna] was on and Kirsten [Vangsness] was on. That was around the time all the other losers got on. We're moments away from being all onboard, which I'm proud to take a tiny bit of credit for. ... [Moore] texted me pretty late last week: 'I'm going to Brazil, but when I get back, I'm signing up for Twitter!'" Gubler says. "I like tweeting as him. Any time I get to play a joke on Shemar, I'm happy, and I think he feels the same. That's some of my favorite stuff. I might just continue doing that!"