Ep 3. Planet of the Ood

The Doctor and his companion, Donna Noble, travel to the Ood-Sphere, a planet that produces Ood, a highly intelligent species with multiple brains that serve as slaves to humans throughout the galaxy. They arrive at the Ood Operations facility, a large factory that processes the Ood for distribution, where they meet the facility's manager, Mr. Halpen.

As they tour the facility, they witness the mistreatment of the Ood by the workers, including electrocuting them to make them compliant. The Doctor and Donna are shocked by the inhumane treatment of the Ood and decide to investigate further. They discover that the Ood's behavior is linked to a neural implant that is forcefully installed in their brains and enables their enslavement.

During their investigation, they discover that the Ood are part of a hive mind and are able to communicate telepathically. The Doctor and Donna are able to communicate with them, and they learn of the Ood's desire for freedom. Meanwhile, Mr. Halpen becomes increasingly resistant to the Doctor's interference and plans to unleash a deadly gas that will kill all the Ood at the facility.

As the situation becomes dire, the Doctor and Donna work to free the Ood from their enslavement and stop Mr. Halpen's plan to commit genocide. They are aided by a sympathetic worker named Solana, who helps them shut down the neural implants. However, the effort leads to a dangerous situation, and the trio is forced to make a daring escape from the facility.

As they flee the planet, the Doctor and Donna are confronted with the harsh reality of the galaxy's reliance on slavery as they witness a shipment of Ood being sent off to another planet. The episode ends with the Doctor reflecting on the Ood's plight and promising to continue fighting against injustice and oppression throughout the galaxy.

"Planet of the Ood" is a gripping episode that explores themes of slavery, oppression, and the struggle for freedom. It highlights the plight of the Ood, a highly intelligent species that has been reduced to slavery, and the Doctor's determination to fight against injustice. The episode features engaging performances by David Tennant and Catherine Tate, who convey a range of emotions as they encounter the Ood's suffering. With its thought-provoking themes and thrilling storyline, "Planet of the Ood" is a standout episode of Doctor Who's fourth season.