"In "Pack Mentality," the Doctor and Rose land in Stoneybridge, England, in 1911, during the eve of a full moon. The Doctor, fearing for his safety, decides to transform himself into a human, taking the guise of a schoolteacher, while Rose pretends to be his housekeeper. Unbeknownst to them, the town is home to a pack of Wolfbloods, a species of humans who can transform into wolves at will.
The Doctor and Rose soon realize that something is amiss in Stoneybridge, as people are going missing on the nights of the full moon. They initially assume that the Wolfbloods are responsible and are determined to put a stop to it. However, their investigation leads them to Rhydian, a young Wolfblood who is trying to keep his true nature a secret from his human friends.
Rose is shocked to learn that the last pack of Wolfbloods was exterminated by humans in 1934, and that Rhydian himself was killed in 1925 during an ambush by hunters. The Doctor is outraged and decides to take action, not wanting another species to be wiped out under his watch.
As the Doctor and Rose work to uncover the truth behind the disappearances, they begin to understand the Wolfbloods and their struggle for survival. The Doctor becomes fascinated by the species and uses Rhydian as a case study, while Rose is hesitant due to her past experience with werewolves.
Despite the risks, the Doctor decides to change history for the better, ensuring that Wolfbloods and humans can coexist peacefully. He drops Rhydian off in 2023 Cardiff, where he will hopefully have a better life.
"Pack Mentality" has a powerful message about the importance of acceptance and understanding. Through their experiences with the Wolfbloods, the Doctor and Rose learn that all creatures have the right to live and thrive, and that it is up to us to ensure that they do. The episode spans various time periods, highlighting the ongoing struggle between humans and Wolfbloods, and encouraging viewers to embrace those who are different from themselves."