Doctor Who's twentieth story is what is called a "Shaggy God" trope. Specifically the term is meant to describe any type of story where Biblical events are given a Science Fiction explanation, such as Adam and Eve being astronauts or Ezekiel's chariot being a UFO. It works for nearly any great legend and literature of antiquity, however, including the Trojan War. Who better to double as Zeus but the irrascible old original Doctor?
Odysseus, the crude and uncouth sailor, has no use for the idea that The Doctor is the father of the gods. Achilles, on the other hand, credits him with the triumphant victory over Hector. Of course, Achilles has carefully chosen to "elaborate" his lucky near-defeat into the legendary battle documented by Homer. Were it not for the distraction caused by the sudden appearance of The Doctor, Hector would surely have skewered him. While Achilles and Odysseus debate it out and Agamemnon pettitions The Doctor to help the destroy their enemies, Steven is captured by the Greeks and the TARDIS is hauled off by the Trojans.
In the midst of the city, Vicki emerges from the blue box and is immediately considered a prophet, much to the chagrin of Priam's daughter Cassandra. She also catches the eye of young Troilus, especially after Priam gives Vicki the more ordinary and respectable name "Cressida". Steven escapes the Greeks and lands himsefl a captive in Troy, doing so under the assumed name of "Diomede". Inadvertantly, they have set in motion the tragedy later recorded by Shakespeare. Or have they? As we have seen, the ancient legends may not mirror quite what The Doctor and his companions have seen with their own eyes.
That question hangs over the head of the TARDIS crew. The Greeks expect "Zeus" to help them win the war or they will execute him as a fake. Can he entrust his own fate to the vagueries of ancient poetry or will he fulfill the prophecies of Troy's destruction himself? Meanwhile, the Trojans expect "Cressida" to prophesy their victory or else. What is she to do, knowing full well the terror coming to Troy in the last days of the war?
There is one last piece of the puzzle, and that is the destiny of Cressida and Troilus. This starcross'd affair is utilized by the writers to dispense with another member of the TARDIS crew. For the first time it's not the Daleks that rip the hardy bunch of companions apart. Yet like Susan before her, it is love that pulls Vicki from her intergalactic explorations. As Troy burns, Cressida and Troilus meet up with the party led by Aeneas. In their presence, she is able to turn her "prophetic" foreknowledge into an omen about the creation of a new Troy, a new nation on a far shore.
Not strictly historical, The Myth Makers could almost be considered a third class of Doctor Who stories: the literary, drawing its inspiration from the celebrated works of Homer, Virgil and Shakespeare. Yet this is curiously not done with a mind to encouraging an investment in classical literature. The "shaggy god" elements deviate from the original texts almost on a one-for-one basis. It nearly hearkens to the joke of Biblical scholarship that is epistemological cynicism. Every time the Bible says someone like King David was a hero, a would-be scholar automatically treats them as an abject villain. If the Good Book says that Jesus was celibate then He must have been married, and so on. If Homer says Achilles was a mighty warrior slaying Hector, then episode writer Donald Cotton makes him a coward who scored by sheer luck. If it does prod one towards the literature, it is merely to see how it twists and tangles it.
The Myth Makers is one of the stories lost to the infamous BBC video purges. Currently only a few snippets from the various episodes exist, all of which can be found on the Lost in Time DVD collection. The fullest document remains the soundtrack, which exists in its entirety and which the BBC has released on CD with linking narration by Peter "Steven" Purves. Most recently, the BBC has released Doctor Who: The Lost TV Episodes: Collection One: 1964-1965, a five story set including Marco Polo, The Reign of Terror, The Crusade, Galaxy 4 and The Myth Makers.
Back on the TARDIS, The Doctor and an injured Steven must grow accustomed to their new companion: Katarina, a Trojan servant girl convinced that she has died and now resides with the gods in their celestial temple. Our Time Lord is primarily worried with finding proper medicine for Steven, hoping that their next destination will deliver. Unfortunately, they land on the planet of Kembel and in the midst of the conflict promised by Mission to the Unknown.