Turn on all the lights and hang on to your blankie, because the new "Insidious: The Last Key" trailer is here to give us all nightmares.

"The Last Key" is the fourth installment in the franchise (although the second in the chronology). It follows parapsychologist Dr. Elise Rainier (Lin Shaye) who investigates supernatural disturbances at the house she lived in as a child. There's no place like home — for demons and ghosts from the Further Realm to terrify you day and night.

The trailer is packed with jump scares and horrified expressions from Shaye, Tucker (Angus Sampson), and Specs (Leigh Whannell). Whannell also wrote the script, as he did the previous movies, with Adam Robitel directing.

The tone and look of the movie seem about the same as the previous installments, which means you may want to sleep with a light on afterward.

"Insidious: The Last Key" opens in theaters January 5.