Ruby (2021) Plot Summary & Ending Explained

The climax of Ruby Gillman, Teenage Kraken sees the titular protagonist confronting the film's twist villain, Chelsea, who reveals herself to be the nefarious mermaid queen Nerissa. To save the town of Oceanside, Ruby must bridge the generational divide in her family, uniting her mother Agatha and grandmother Grandmamah to fight a common enemy. The three generations of krakens combine their powers to destroy the Trident of Oceanus, the source of Nerissa's strength. Once the weapon is shattered, Nerissa is stripped of her power and shrinks back to the size of her human disguise. In a fitting turn of events, she is promptly captured by Gordon Lighthouse, the town’s sea monster enthusiast, who traps her in a cage. This fate serves as a poetic justice for a character defined by manipulation, contrasting her imprisonment with the freedom Ruby finds through honesty.

This victory facilitates a heartfelt reconciliation that resolves the film's central conflict: the danger of keeping secrets. Throughout the movie, Agatha hid Ruby's heritage to protect her, while Ruby hid her actions to avoid disappointment, leading to a cycle of "omissions" that nearly tore them apart. The ending brings these truths to light, with Agatha promising "no more lying" and Ruby vowing "no more hiding." By defeating the mermaid queen, the family proves they are stronger together than apart, finally healing the rift caused by Agatha’s over-protectiveness and Grandmamah’s rigid expectations.