Hardcore horror audiences won’t find much that’s frightening in Insidious: The Last Key — there’s not even that wonderfully unsettling shriek of violins under the title this time — but as a delivery system for more great work from Lin Shaye, it more than accomplishes its mission.

Insidious: The Last Key may be somewhat engaging but it’s also sloppy and doesn’t amount to much.

A workmanlike but fan-pleasing picture.

Hard-core fans get the loud noises they came for, but true fear vaporizes.

The fourth installment of the Insidious series has deft scares and some nifty twists, all of which don’t entirely distract from how strangely inconsequential The Last Key ultimately feels.