How is it possible that no one has done anything quite like this before? I mean, how often have you watched a horror movie and moaned, “Don’t these people realize they’re in a horror movie? Why don’t they behave in a more appropriate manner to what’s happening around them?” Well, here it is. Except — ooops — while everyone is acting like they’re in a horror movie, they’re actually in a comedy. Oh, dear. Oh, my. Oh, goody. This is one of the funniest things I have ever seen, a clever, witty, surprising splatter comedy to rank with Evil Dead II and Shaun of the Dead. I’m not sure how well it will hold up on a repeat viewing, but I suspect quite well indeed, because Tucker and Dale are two very sweet guys, and their adorable utter confoundment at finding themselves in their, er, situation is compulsively watchable… and it makes them endlessly sympathetic. Because they aren’t the ones behaving like they’re in a horror movie: they’ve only gone out to Tucker’s (Alan Tudyk: Transformers: Dark of the Moon) fixer-upper cabin in the woods for the weekend to do some reno work when along comes a gang of college kids on a camping trip who get a gander at these two “redneck hillbillies” and get the completely wrong idea about them. So when shy Dale (Tyler Labine: Rise of the Planet of the Apes) rescues pretty Ally (Katrina Bowden) from a swimming mishap, a cry across a nighttime lake of “We got yer friend!” is bound to be misinterpreted. Mix in all the dangerous tools to be found around any DIY home-improvement project — chainsaws; wood chippers — and, well, accidents are bound to happen. This first feature from director Eli Craig (who cowrote with Morgan Jurgenson) is a sly little masterpiece of yucks and the yucky, one with a very welcome undercurrent of a warning not to make assumptions based on first appearances. Or at least not to run with the proverbial scissors, or the not proverbial wooden stake.