Ten years ago, Timothy Haskell started making haunted houses on virtually no budget. But with a passion and talent for terrifying willing participants, he quickly climbed the scaremaster ranks, and is now the creative director and mastermind behind one of New York's hottest and most horrifying haunted houses. Killers is not your standard strip-mall haunt with fake electrocutions and pop-up surprises that make you jump, although those are there too. So how does he do it? "My haunted house is more theatrical than most. All haunted houses need an element of startle," he says. "But they also need to be unnerving, they need to be disturbing, they need to be creepy, and they need to be haunting." For Haskell, psychology reigns supreme. Killers is populated by just that — historical, real life serial killers, portrayed by actors. There's a story throughout. Each scene is designed to produce a different emotion in the viewers, creating empathy for the victims and families before twisting it around. "I do that a lot, where I will take someone out of a group," Haskell says. "Because no matter what, no matter how cynical of a person you are, and how much you know that all this is fake and that you're going to be safe, the one thing that is real is if I take your girlfriend away from you." One of Haskell's favorite tricks is the bait and switch. Anyone can hide an actor or a prop, timed to jump out when visitors are least expecting. But if you can hide the surprise in something guests are aware of, something they think they've got figured out, the payoff can be much greater. "We'll have something that we try to make look like a really crappy animatronic, so that people sort of scoff at it," says Haskell. "It's a way of fooling them, to lull people into a level of comfort. A lot of people at haunted houses like to make fun of things, 'cause it makes them really tough. So give them something to make fun of, and then disarm them because they're trying to impress their friends. As soon as the alpha goes down, everyone else falls like dominos."

Chocolate Brains from 3D-Printed CT Scans If you’ve had the (mis)fortune of having a CT scan of your brain, make sure to ask for the files. You likely won’t be able to diagnose your maladies without years of training and special equipment, but you can use the images to create 3-D objects that have the same capabilities of any CAD file — panning, rotating, manipulating or printing. The team at London-based 3-D printing shop Inition did just that with the brain scan of Andy Millns, Inition's Creative Director, creating a handheld-sized plastic replica of his cerebrum for all to see and hold. But then they took things a step further — they used the model to create a latex mold, which was subsequently filled with chocolate, allowed to harden, and eaten by the possessor of the actual brain. If you want your own pile of scanned grey matter, the Inition team has posted their steps. You’ll need CT scans of your brain, skull, or sprained toe, a 3-D printer, food-safe latex, and some chocolate. And the ability to not get creeped out that you’re eating your own brain. For those without access to CT brain scans and 3-D printers, this Hollywood method uses a sorbitol-glycerin-zinc-oxide mixture and a commercial brain mold — all easily obtainable online. Be aware that the final creation, while edible, is hardly tasty.

Arduino-controlled Singing Busts Whatever barber this barbershop quartet visited took a little too much off the top. But at least they retained their singing voices, thanks to an old karaoke machine. Creator Chris Krueger linked the audio to a VGA projector, and rigged the whole thing to trigger when a photocell switch wired to an Arduino UNO gets tripped. A longtime fan of Disney World, Krueger says his inspiration was to recreate a part of the Haunted Mansion ride with off-the-shelf parts. "Most of my trips to Disney World are spent with me hanging out the side of rides trying to figure out how they're put together," he says. The Styrofoam heads that form the basis don't need much (or any) work, lit up as they are with original video from Disneyland (via YouTube). A look at a Disney patent, via DoomBuggies, shows another way to engineer a disembodied head: Project it in reverse from the inside out and you can hide the source of the projection.

Jacob's Ladder Combine a high-voltage transformer, like the type from a neon lamp, with two conductive metal wires separated into a narrow "V" and you've got the makings of the classic mad scientist desktop prop called a Jacob's Ladder. Watch fingers of electricity climb their way to the top of the metal probes, then disappear and start all over again. Finding the supplies for the project isn't too difficult, and plans abound online. But as with any high-voltage project, special care is required to make sure that no one gets hurt; some write-ups even suggest putting a momentary "on" button into the circuitry for utmost safety.

Double-iPad Gaping Hole in Body Actors are particularly important to haunted houses, but makeup can only take you so far. If you've got $1,000 to spare and an old shirt to tear, you can riff off last year's runaway hit, the guy with a gaping hole in his torso. The genius behind the costume would be NASA engineer Mark Rober, who explains that it's as simple as two iPads connected via FaceTime and a mobile Wi-Fi hotspot. Or, with just one iPad, toss on a visualization of something horrific — say, a still-beating heart — and show everyone what you're made of (literally).

CNC-Routed Pumpkins No haunted house is complete without a jack-o-lantern or two. But knives are so 20th century. The modern DIYer uses a CNC router, like the PlasmaCAM, with the scanned pumpkin dimensions, for his or her gourd art. While hand carvings tend to be limited to basic circles and triangles, laying your design out on a computer lets you up the detail and the pace to incredible levels. As always, bonus points if you incorporate an Arduino for dynamic lighting effects.

<stong>Repaint Your House With Projectors</stong> With the help of a projector or two, you can make your haunted house quite literal. The technique of projection mapping shines a moving image on a structure, often incorporating elements of the building's geometry, to tell a story or just put on a show. Matt Champneys, with the help of his daughter Jessica, timed lightning strikes, falling bricks, and dancing skeletons to match a soundtrack — featuring Rockwell's “Somebody's Watching Me” and scenes from The Corpse Bride — on their house in Utah. Effects were made using DAZ3D and Serif Movie Plus, and the projector shells out 2,500 lumens, but Champneys' treatment is just one of many options — the Bates Haunt, by Dave Bates and family, has been running a projection map for a decade, and the website includes resources and even sells a DVD for DIYers who want a shortcut.

Eerie Instruments As musical instruments go, the Theremin is one of the strangest — think of the classic wail of alien music from The Day the Earth Stood Still. It works by allowing your hand to interrupt the capacitance from one or more antennas (without touching the device at all) thereby altering the frequency and volume. Sound is difficult in haunted houses, says Haskell, because it tends to bleed beyond the scene it's a part of, creating a cacophony. But it's also important to have it individualized to the scene. "The ideal is to be a combination of both, a sort of universal sound that's both scary and daunting and unnerving," he says. Cacophany is a good description of the sound from this Arduino-Theremin mashup created by the Laboratory for Experimental Computer Science at Cologne's Academy of Media Arts. While the decidedly digital, 8-bit sound is not at all horrifying, the Arduino allows for a wide range of other proximity-controlled effects (changing lights, controlling effects, and so forth).

Haunted Hologram Spectral projections may come from the afterworld, but they can also come from an LCD projector, a few miscellaneous computer parts and some household supplies. This DIY system created by Chris Weisbart operates similarly to commercial systems that cost tens of thousands of dollars, but he explains that his cost was in the tens. "You can salvage most of these parts from thrift store computers," he says. "All in all, you can make the thing for under $50. The humidifier cost me $3 at a Goodwill." The screen is built by piping the dry mist from a common humidifier into a long, boxed grid of vertically aligned drinking straws. Two rows of computer fans on either side of the grid control the thin sheet of vapor that rises upward, nearly invisible under normal circumstances but able to catch the projected light. Video shot on a black background gives the best results, creating a ghostly, floating effect that seems to move in three dimensions when a slight breeze disrupts it.