The episode follows Lucy, Lockwood, and George as they descend into the Bone Glass catacombs beneath a cemetery to stop the Bone Glass from being used. They face off against Joplin and the Golden Blade, leading to a confrontation where the true nature of the Bone Glass—and the horrific cost of looking into it—is revealed.

Reviewers from Rotten Tomatoes and Ready Steady Cut praised the episode for its:

: Contrast is drawn between Joplin’s obsessive pursuit of knowledge and the trio’s willingness to sacrifice themselves for each other.

: Lockwood’s struggle with his parents' history and the literal ghosts of his house sets the stage for future growth.

: The bond between the central trio is cemented, moving them from mere business partners to a found family.

: The central conflict resolves as the team discovers the glass is actually made from the mirrors of the "seven," trapping souls to create a window to the "Other Side."

The Season 1 finale of Lockwood & Co. , titled "Not the Chosen One," is a high-stakes conclusion that balances a tense supernatural heist with significant character revelations.