Ep 8. 42

The Classic Doctor Who series features the third season, which consists of 45 episodes. The eighth episode of the season is named 42 and was initially aired on May 19, 2007. This episode was directed by Graeme Harper, and the screenplay was written by Chris Chibnall. The episode features the tenth Doctor played by David Tennant and his companion Martha Jones played by Freema Agyeman.

The episode 42 is set in the future where a spacecraft named SS Pentallian is on its way to the planet Orbis. However, the ship's crew is in trouble as they have been possessed by an unknown entity that has labeled them as 'Them'. The Doctor and Martha get on board the ship to help the crew since they have received a distress signal. The Doctor soon realizes that the ship's basic state is 42%, and they only have 42 minutes to save the ship from falling into the sun.

The Doctor and Martha find that the possessed crew members are controlled by a sentient star that requires a host. The entity jumps from one crew member to another, possessing them and using their knowledge to solve the puzzles protecting the ship. The Doctor and Martha realize that the solution lies with the ship's engines, which are powered by a substance that is the equivalent of the sun's plasma. The entity, however, does not want the engines to start, and hence, keeps sabotaging the ship.

With time running out, Martha and the remaining crew members try to restore the ship's power while the Doctor confronts the entity. During the confrontation, The Doctor discovers that the entity was brought aboard the ship by the ship's captain, who was trying to use the entity's power for personal gains. The Doctor tries to persuade the entity to leave the crew and end its existence by jumping into the sun. The entity agrees, and the Doctor sends it off into the sun, saving the ship and the crew members.

Overall, the Classic Doctor Who season 3 episode 8, 42, is an intense science fiction thriller that keeps the viewers on the edge of their seats. The episode features a tense atmosphere, and the plot is well-paced with plenty of twists and turns. The episode's highlight is the excellent chemistry between David Tennant and Freema Agyeman, and their performances leave a lasting impression. The special effects used in the episode are also of high quality and effectively add to the overall ambiance. The episode is a must-watch for science fiction and Doctor Who fans alike.