The first novel in the Doctor Who New Adventures. In space above the planet Earth, two starships are locked in a violent confrontation. One ship is destroyed, a survivor escaping the conflagration. In ancient Mesopotamia, Gilgamesh, King of Uruk, is exploring the desert when he comes across this survivor, who claims to be the goddess Ishtar. When Gilgamesh turns her down, she goes to the rival city of Kish where she begins to plot to take over Earth.
Meanwhile, in the TARDIS, Ace wakes up without any memories. She explores the ship and finds the Doctor, where he is confronted by an image of his fourth incarnation, warning him about something called the Timewyrm. They arrive in Mesopotamia, where they meet Gilgamesh, his Neanderthal right-hand man Enkidu and explore the city of Kish. They learn that Ishtar has insinuated herself in the city and is effectively in control of it, using implants and manipulation to control the city's military and leaders.
- Beethoven Was an Alien Spy: Enkidu is a Neanderthal, Ishtar is the Timewyrm. Gilgamesh and Enkidu fight a cybernetic construct.
- Demythification: All the events of the Epic of Gilgamesh are shown or implied to have non-supernatural explanations. (This being Doctor Who, "mundane" wouldn't be quite the right word.) Enkidu is a neanderthal, Gilgamesh is a perfectly human Boisterous Bruiser... and Utnapishtim is an alien starship captain, his flood-defying ark is a spacecraft, and the Scorpion Men are robots with lasers. Oh, and Ishtar is being impersonated by an alien criminal who Utnapishtim is trying to hunt down.
- Easy Amnesia: Ace has some at the beginning, which goes away once all the As You Know exposition required to set up the series has been delivered.
- Floating Head Syndrome: The cover illustration features the Doctor's head in this style.
- Info Dump: As the first book of the series, it starts off with a scene where Ace conveniently has amnesia, allowing the Doctor to rattle off his identity, her identity, her real name, her background, the premise of Doctor Who itself, and key locations like the TARDIS and Gallifrey, and even adds in a Cameo from the Fourth Doctor (the most iconic Doctor, easily recognised by even non-fans) in the form of a recorded message so the Doctor can explain to Ace and the reader that he and that person are the same character.
- Literary Allusion Title: To the Book of Genesis.
- Mesopotamian Monstrosity: Ishtar.
- Misery Builds Character: The Doctor uses this as an excuse for abandoning Ace in the company of an increasingly drunk and horny Gilgamesh. Luckily, Enkidu is present in the role of the Only Sane Man. In the whole of Mesopotamia.
- Phantasy Spelling: Genesis spelled Genesys.