"Master Chief Meets Guilty Spark" is the second episode of season 3.
Johnson questions the King about the Burger King advertisements and video games, to which the King says he made for extra cash. 343 Guilty Spark arrives and tells them that he brings a message from Master Chief and the Arbiter, who are in the year 2020. Johnson is hostile towards Guilty Spark, but the King appreciates the message. After Guilty Spark departs, the King agrees to tell Johnson his plan to get back to the future, which requires the help of an "old friend." The friend is revealed to be Ronald himself.
After a short "previously" segment, Master Chief and the Arbiter refuse to trust Guilty Spark until he reveals he has the ability to time travel. He departs to give a message to the King and Johnson. The Arbiter suspects that since Guilty Spark was created by the Ancients, his helpfulness is a ruse and he is setting a trap. When Guilty Spark returns, he reveals the King and Johnson were sent to the year 44 BC, and that because he is an AI like Cortana, he can help reunite them.
- This episode was released on the two year anniversary of Halo 3. In the show, Master Chief's birthday is September 25, 1993.
- Guilty Spark is different from the rest of the characters in the series for several reasons. Aside from his scripted human voice, he also has a different, more robotic subtitle font and does not have his own image when he speaks. Instead, he moves around the other characters to whom he is speaking.
- Johnson's hostility towards Guilty Spark is a reference to the fact that in Halo 3, Guilty Spark kills Johnson. Guilty Spark also repeatedly betrays Master Chief and the Arbiter, explaining their reluctance to trust him.
- 44 BC is the year that Julius Caesar was assassinated.