The battle over the Omega Key leads to decisions that can't be undone — and a dangerous door that promises plenty of trouble ahead.
Nina drinks coffee with Detective Mutuku, she is angry that she has lost six years worth of sobriety, however he remarks that it does not erase the progress she has made over the last few years. Nina tells the detective that she thought Matheson would’ve been a fresh start, but it seems as though they made the wrong choice, and Matheson is perhaps not healthy for them.
At Keyhouse, Tyler, Kinsey and Bode wait for Ellie, however, find that Dodge is approaching the house. She brings the Crown of Shadows and, placing it upon her head, commands the shadows around her. Tyler believes the shadows to be harmless, however, when Dodge launches a car across the drive, they believe otherwise. They quickly barricade the door, however, they are unable to stop the shadows entering through doorways; this allows Dodge’s shadow to enter. One of the shadows begins emptying Rendell’s urn, however, is unable to find the Omega Key.
Bode realizes that turning on the lights ensures that the Shadows cannot enter the house. Bode fashions a weapon out of the Matchstick Key by attaching it to the end of his lightsaber. The power suddenly cuts, allowing the shadows to return. Kinsey descends to the basement to trip the fuse board, however it attacked by multiple shadows who begin fighting over her; she is able to fend them off initially with a match, however. Meanwhile, Bode stabs Dodge’s shadow with the Matchstick Key, causing it to explode. This also incapacitates Dodge but does not kill her. They are unable to find the Crown of Shadows, however, and Tyler questions if the Omega Key is still safe, revealing it to be hidden in the Mending Cabinet. Tyler suggests putting Dodge back into the Well House, however, they do not have the Echo Key; Kinsey suggests using the Omega Key to put Dodge back through the Black Door.
Tyler and Kinsey call in backup to carry Dodge to the Drowning Caves, these include Gabe, Scot, Eden, and Jackie. They carry the body to the caves, but Scot is worried about the tide situation, given what had previously happened with the Savini Squad. When they arrive at the Black Door, Kinsey changes her mind, believing that they are doing the wrong thing. Tyler reveals that they should hurry, given the tides are about to rise. They decide that the only option is to open the door and, opening the door, they’re pleasantly surprised with what they find. They throw Dodge in and are eventually able to shut the door, locking it with the Omega Key. Returning home, the group is relieved at their recent experience, and they decide to eat before going their separate way. Scot talks with Kinsey, and he tells her that he has been thinking a lot about double-dating Kinsey; he tells her that it is not something that he is interested in, and the two call it quits on their relationship, but promise to remain friends.
Bode, meanwhile, bikes to the Whedon house to check on Rufus and Ellie. He finds Rufus unconscious on the floor but is unable to wake him. He calls the police, forcing Detective Mutuku to end the coffee date with Nina. Bode questions Rufus over what happened, however, he is unable to tell him anything about Nina, other than the fact that he saw Lucas turn himself into Dodge. He gives Bode the Head Key and the two part ways.
Returning home, Bode questions the events surrounding the Dodge situation. Bode asks if they’re sure that the woman they threw through the door is Dodge. Tyler assures Bode that Dodge is gone, given the fact that they both saw her get swallowed by the other side of the Black Door. The next morning, Duncan returns back to Matheson whilst Nina makes breakfast for the children. Nina tells the children that nobody has heard anything about Ellie, which worries Tyler, Kinsey, and Bode. Nina tells the children that she made a mistake moving them to Keyhouse Manor, and now they are going to move back to Seattle if they sell the house. The children are not happy with the announcement, however, and tell Nina that they like Matheson and do not want to move back to Seattle.
Bode writes a letter to Rufus, wishing him well with his stay in Nebraska, and reveals that he is trying to figure out what happened to Ellie, given she has still not been seen since they threw Dodge through the Black Door. Bode tells Rufus that the keys were fun at first, but are now a part of who they are and they must protect them; he dubs them the new Keepers of the Keys. Bode tells Rufus he will visit Nebraska with the Anywhere Key if they manage to retrieve it someday.
The Locke Family takes a trip to the cliffs above the Drowning Caves to spread Rendell’s ashes into the wind.
Later, Kinsey arranges to have dinner with Gabe at Phil’s, whilst Tyler goes fishing with Jackie’s family. Everything seems normal; however, Gabe is seen riding his bike to meet Kinsey, while a series of flashbacks reveal that Dodge changed Ellie’s appearance to resemble herself with the Identity key, therefore the Dodge that they threw through the Black Door was actually Ellie, and that Eden was hit with one of the demons when the Black Door was open previously. It is revealed that all along, Gabe has been Dodge, as Dodge meets with the now possessed Eden.
- Dodge uses the Crown of Shadows to attack Keyhouse Manor.
- The Black Door is opened for the first time on-screen; this marks the first use of the Omega Key in the series.
- Bode takes possession of the Head Key from Rufus.
- Bode reveals that the Anywhere Key is still missing, however it is revealed at the end that Dodge still has the key.
- The Locke Children and their friends believe they have thrown Dodge through the Black Door, however it is revealed to actually be Ellie Whedon.
- Gabe is revealed to be a disguise Dodge created to get close with Kinsey.
- Nina tells the children they can move back to Seattle and sell Keyhouse Manor, however they object.
- Rendell's ashes are spread on the top of the cliffs at Drowning Cave.
- Eden is hit by a demon when the Black Door is open, transforming her into a demon.
- The paramedics tending to Rufus are played by Locke & Key creators Joe Hill and Gabriel Rodriguez, like they did in the comics.
- Tyler is seen wearing a cap with a fishing lure on the visor, similar to the cap the comic character wears.