It does, and it makes you appreciate Elise's heroics more -- you'll understand the adversity she's had to overcome and the sacrifice she's making every time she undertakes a job. In New Mexico, Elise grows up the older sister of a boy terrified of ghosts he can't see and the mischievous daughter of a strict prison warden father. By the time she's grade-school age, she's communing with spirits and opening doors that should be left closed. Things are rough for the always-in-trouble Elise from the get-go, but they get worse when she accidentally acts as a conduit for KeyFace, a sinister spirit that facilitates the death of her mother. As Elise's father sees it, Elise's phony "gifts" are a pox on their house. For Elise, from an early age, her gifts become a source of great trauma. These are her terrible beginnings, and, with the help of her trusty sidekicks, Specs and Tucker, she seeks redemption in the present by confronting the demons of her past.
For much of the movie, Robitel tries to capitalize on the spooky things that scared you as a kid: dark closets and basements, antiques, creaky floorboards, doors that move by themselves. The tactics are true to the atmosphere of what makes an Insidious movie an Insidious movie, but unfortunately, much of the ghost-hunting jumps that ensue feel predictable and too familiar. Long-time Insidious fans will feel like they've already seen the ghosts-lurking-behind-people's-shoulders trick, some might cringe at the forced romantic subplots given to Specs and Tucker (now comic relief on steroids), and it'll be hard not to ask, "What? Why?" amid the tortuous stretch it takes to bring KeyFace front and center for what is ultimately a brief, unfulfilling showdown. The saving graces of the movie are undoubtedly Shaye, as strong as ever as Elise -- her fright is convincing and so is her conviction, even when delivering potentially cheesy lines like, "I don’t have memories from this place, I have scars" -- and that dark realm "The Further," where some of this movie's best low-key magic happens.
When Elise finally leaves her body, we're reminded, like in the second installment, that The Further is a realm in which time doesn't operate the way we think it does. She opens a door on a red-caped little boy climbing a ladder in his attic, a reveal that predicts and links the events of this movie directly to the first. The shout-out gets a nice exclamation point at the very end, when Elise wakes up to a call from Lorraine Lambert. Elise finishes her former client's sentence for her -- she knows Dalton's in trouble, already having seen the Lipstick-Face Demon. With the chronological loop of the saga tied in a nice bow, you might think that this is it for the saga. (Recall: Our heroine Elise technically dies at the end of the first, or next, movie.) But what's nice about the way The Further is used in The Last Key is that it actually leaves another story door slightly ajar.