Ben 10 Season 2 Episode 10 — "They Lurk Below"

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The second season of the original Ben 10 animated series plunges into uncharted territory by diving into the deep blue sea. The journey drops beneath the ocean waves in Episode 10, "They Lurk Below," as a relaxing trip to an engineering marvel transforms into a claustrophobic survival mission against an aggressive aquatic threat.

The Tennyson family is invited to get an exclusive sneak peek at a revolutionary, high-tech underwater resort engineered by one of Grandpa Max's lifelong friends. However, what starts as an incredible vacation rapidly deteriorates into a crisis when mysterious mechanical aliens launch a relentless assault to reclaim a stolen alien artifact powering the facility.

“When you build a paradise in the depths of the ocean using things you don't understand, the real monsters will eventually come up to drag it back down.”

Episode Summary

Grandpa Max takes Ben and Gwen to visit his eccentric old friend, Donovan Grand Smith, who has constructed "Submarina," a state-of-the-art underwater hotel located at the bottom of a deep ocean trench. Donovan's arrogant grandson, Edwin, instantly clashes with Ben's casual attitude, sparking a fierce rivalry between the two pre-teens.

The celebration is cut short when strange, robotic deep-sea creatures attack the structure, rupturing the hull. Max uncovers the truth: Donovan managed to build and power the resort by salvaging a highly volatile energy orb from a sunken alien spacecraft. The creatures attacking Submarina are actually automated drones attempting to retrieve their lost tech, and their assault threatens to collapse the entire facility under extreme oceanic pressure.

As the resort floods, Ben is forced to utilize aquatic forms like **Ripjaws** to navigate the submerged corridors and protect the group. However, the drones prove too versatile under water, trapping the boys in a damaged submersible. Working together, Ben and Edwin set aside their differences to override the sub's systems, using **Upgrade** to bypass a massive group of drones. Recognizing the danger of their greed, Donovan returns the power source, allowing Ben to rescue the remaining survivors just before Submarina is totally destroyed.

Themes & Character Development

The Cost of Arrogance: Donovan and Edwin reflect a wealthy, tech-reliant mindset that mimics Ben's early immaturity, showcasing how ignoring boundaries for profit leads to severe consequences.
Shattering Rivalries: Ben and Edwin's growth during the crisis demonstrates that mutual respect and survival can break down superficial class divides and petty competitive egos.
Environmental and Cosmic Boundaries: The story serves as a reminder that mankind's exploration shouldn't exploit cosmic forces beyond human understanding, emphasizing balance and humility.

Production Details

First Aired: July 18, 2006
Created By: Man of Action (Duncan Rouleau, Joe Casey, Joe Kelly, and Steven T. Seagle)
Written By: Thomas Pugsley and Greg Klein
Directed By: Sebastian Montes
Produced By: Cartoon Network Studios
Art Style: Captures an immersive, atmospheric deep-sea aesthetic characterized by murky blue lighting, glowing bioluminescent alien technology, and intense claustrophobic framing.
Voice Cast:
- Tara Strong as Ben Tennyson
- Meagan Smith as Gwen Tennyson
- Paul Eiding as Grandpa Max
- Tom Kane as Donovan Grand Smith
- Vansay Khamphommala as Edwin Grand Smith

Fun Facts & Trivia

Did You Know?

"They Lurk Below" is celebrated by the fandom for featuring the most prominent, heroic, and extended screentime for **Ripjaws**, an under-utilized alien in the original starting lineup.
Donovan Grand Smith is voiced by Tom Kane, the legendary voice actor known for voicing Yoda in *Star Wars: The Clone Wars* and Professor Utonium in *The Powerpuff Girls*.
The sub-aquatic resort "Submarina" serves as a direct conceptual homage to legendary sci-fi underwater settings, most notably Jules Verne's *20,000 Leagues Under the Sea*.
Donovan Grand Smith's character makes a notable return in the alternate future episode "Ben 10,000," proving that he remained a reliable friend to the Tennyson family for decades.
This episode showcases a rare scenario where the "villains" are actually autonomous security programming justified in their actions, as they are simply recovering property stolen by humans.

Legacy & Impact

"They Lurk Below" stands out as an excellent, self-contained adventure that maximized the versatility of Ben's alien database by forcing him into a hyper-specific terrain. By utilizing Ripjaws in his native habitat, the episode added significant variety to the series' combat formulas, ensuring that environmental factors felt like genuine obstacles to the characters' survival.

The ultimate strength of **Ben 10** is rooted in accountability. This underwater trial proves that acknowledging a mistake and surrendering an unearned power source is the ultimate step toward preserving life, showing that letting go of pride is the hallmark of a true hero.