Ep 1. Welcome to Area Fifty-Something

The show Monsters vs. Aliens follows the adventures of a group of monsters who are recruited by the US government to protect Earth from alien threats. The first episode of season 1 is titled "Welcome to Area Fifty-Something."

The episode begins with a spaceship crashing into a desert near a secret government facility called Area Fifty-Something. The facility is home to various monsters who are being held captive there. The monsters include Susan Murphy, a woman who was transformed into a giant by a meteorite; Dr. Cockroach, a mad scientist who turned into a bug after experimenting with his own DNA; B.O.B., a gelatinous blob with no brain; and The Missing Link, a fish-ape hybrid who had been frozen in ice for thousands of years.

The monsters are introduced to their new handler, General W.R. Monger, who tells them that they are the only hope for Earth's survival against the alien threat. The aliens, known as the Gallaxhar, are a highly advanced species that are on a mission to retrieve a substance called quantonium, which is essential for their survival.

Monger assigns Susan, Dr. Cockroach, and B.O.B. the task of investigating the crashed spaceship and retrieving any information they can about the Gallaxhar's plans. The team sets out on their mission, but they quickly realize that they are not alone. The Gallaxhar have sent a giant robot to retrieve the quantonium from the crashed spaceship.

The team manages to infiltrate the robot and retrieve the quantonium, but they are discovered by the Gallaxhar. A vicious fight ensues, and the team manages to destroy the robot. However, they learn that the mission was just a diversion, as the Gallaxhar had already retrieved the quantonium from another location.

The team returns to Area Fifty-Something, where they are hailed as heroes for their bravery. Meanwhile, the Gallaxhar prepares for his final assault on Earth, and the monsters realize that they have a tough battle ahead of them.

Overall, the first episode of Monsters vs. Aliens sets up an exciting premise for the series. The animation is bright and colorful, and the characters are all unique and likable. The action scenes are well-done, and the plot keeps viewers engaged throughout. The episode also establishes the ongoing conflict between the monsters and the Gallaxhar, which sets the stage for future episodes.