Plumber Headquarters

The Plumber Headquarters is a location that appears in Ben 10: Alien Swarm and Ben 10: Omniverse. It is a functional Plumber Base, leaded by the Magister of Earth, Max Tennyson. One of the entrances is through the Max's Plumbing shop bathroom.

Ben 10: Alien Swarm
It was first seen when Ben went to Grandpa Max to ask about the Nanochips.

The More Things Change: Part 1
It re-appeared in The More Things Change: Part 1, when Ben visited his grandfather, Max.

Trouble Helix
Ben was training with Blukic and Driba. Khyber infiltrated the base to get informations about Ben and Malware.

It Was Them
Rook and Ben checked Dr. Animo's cell.

Outbreak
It was invaded by Dr. Psychobos and his robots. After the Omnitrix malfunctioned, some prisoners were transformed into some of Ben's aliens. The prisoners tried to escape from the prison, but were defeated by Ben, Rook and their team.

Ben 10: Alien Force

 * Ben 10: Alien Swarm (first appearance)
 * Fool's Gold

Ben 10: Omniverse

 * The More Things Change: Part 1 (first re-appearance)
 * The More Things Change: Part 2
 * Trouble Helix
 * It Was Them
 * Outbreak
 * Blukic And Driba Go To Mr. Smoothy's
 * Arrested Development
 * Ben Again
 * Store 23
 * The Frogs Of War: Part 1
 * The Frogs Of War: Part 2
 * Rad

Trivia

 * The Plumber Headquarters is similar to the "Prison 42" from the TV show The Avengers: Earth's Mightiest Heroes.