When a producer proposes that screenwriter Grace Mitchel craft a horror tale set in an old hotel, the long-deserted Lyndora appears to be the ideal muse. This early 20th-century hotel is infamous for its turbulent and unsavory history—the rooms have been sealed for half a century following a string of brutal murders—and local legends claim it is haunted. Despite the concerns of her family and friends, a determined Grace moves into the spooky inn to fully immerse herself in her writing. However, with the doors now unsealed, the hidden truths of the past start to surface. As unsettling yet seemingly rational events begin to intensify, Grace finds herself struggling to distinguish reality from madness, embarking on a descent into darkness from which some may never return.