Classic Doctor Who Season 19 Episode 5 Four to Doomsday: Part 1

When the TARDIS materializes near an enormous spaceship belonging to the Urbankans, the Doctor and his companions are curious to investigate. They quickly learn that the Urbankans, led by their ruler Monarch, have come to Earth for a mysterious reason involving the number four. As the travelers explore the ship, they encounter a variety of aliens from different planets, all of whom seem to be there for a specific purpose.

But when they discover Monarch's true intentions, the Doctor realizes that the stakes are much higher than he initially thought. With the help of his companions and a group of rebels on board the ship, the Doctor must stop Monarch from enacting his dangerous plan before it's too late.

Meanwhile, Adric finds himself drawn to the allure of the advanced technology on the ship, and struggles with his desire to help the Doctor versus his own selfish interests. As tensions rise and timelines run short, the travelers must work together to save the universe from certain doom.