I love horror movies that use tension more than gore -- though good special effects are always welcome, too. Films like Evil Dead make me smile. Films like Insidious make me leave a nightlight on.

Director James Wan, with nods to The Exorcist, Don't Look Now and other fine examples of possession horror, is excellent at producing a ton of pressure out of very little, opting for good camera work and eliciting help from a great soundtrack to create masterfully orchestrated scenes of almost unbearable stress. It doesn't do anything new, showing its influences far too much to achieve originality, but it's admirable for the way it dresses up old-style ghost films with remarkable skill.

A seemingly normal, happy family, Josh (Patrick Wilson) and Renai (Rose Byrne) and their two adorable sons, have moved into their dream home, experiencing strange occurrences before the first box is unpacked. Things move around; noises from the attic are calling out to the eldest son, Dalton (Ty Simpkins), tempting him to go places he shouldn't; and demonic hand and footprints are appearing everywhere. After Dalton goes into a coma after a fall in the attic, the family moves, only to find the terror has followed.

Realizing that it's not the house that's haunted but the child, the grandmother (Barbara Hershey), in a huge tip of the hat to Poltergeist, calls in a psychic (Lin Shaye), who works with two ghost-hunting geeks and whose antics make for one of the movie's two sour notes that drag it down. The casting of Hershey is particularly brilliant, given how much the film owes a debt to her classic film, The Entity.

The team quickly determines that Dalton has become lost in the spirit world, to which he had created a portal with his ability to travel the astral plane in his sleep. During his travels, he unwittingly attracted the attention of a demon that possessed him with the intention of using his portal-walking abilities for its own evil ends. The only solution is to cross over and bring him back.

Wan has achieved his scares without the buckets of blood he used in the Saw franchise he launched. He eschews typical jump scares for real jolts and quality storytelling that's good enough to push past Insidious's obvious calculations. The craziness to which it descends in the second half is the other sour note that threatens an otherwise great movie.

Apart from that, though, Insidious works very well and is a decent homage to the excellent horror films that precede it. It's grim and weird and scary without being gory, managing to create a sort of old-fashioned horror films by allowing their idiosyncratic sensibilities to charmingly reframe a well-mined genre that sustains its scares very well.