Timewyrm: Genesys (novel)

Publisher's summary
Mesopotamia -- the cradle of civilization. In the fertile crescent of land on the banks of the rivers Tigris and Euphrates, mankind is turning from hunter gatherer into farmer, and from farmer into city-dweller.

Gilgamesh, the first hero-king, rules the city of Uruk. An equally legendary figure arrives, in a police telephone box: the TARDIS has brought the Doctor and his companion Ace to witness the first steps of mankind's long progress to the stars.

And from somewhere amid those distant points of light an evil sentience has tumbled. To her followers in the city of Kish she is known as Ishtar the goddess; to the Doctor’s forebears on ancient Gallifrey she was a mythical terror -- the Timewyrm.

Preface
A spacecraft, holding the mysterious Timewyrm drifts into Mutter's Spiral. The Timewyrm is possessing the crew, but kills them all when they frustrate her. She plans to set up a slave world on Earth, but soon realises the ship is falling apart. As she meets her apparent death, she can only see the irony in this.

Characters

 * The Seventh Doctor
 * Has enhanced night vision.
 * Ace
 * Gets temporary amnesia.
 * Sings Irish folk songs.
 * Drinks beer that tastes not quite unlike pig vomit.
 * Ishtar (aka Qataka)
 * Gilgamesh
 * Has wandering hands; Ace consequently wears layers to protect herself.
 * Ninani
 * daughter of King Agga
 * Utnapishtim
 * Agga
 * Avram
 * Belkeli
 * priestess of Ishtar
 * Dumuzi
 * high priest of Ishtar
 * En-Gula
 * Enkidu
 * a Neanderthal
 * Ennatum
 * Gudea
 * Lagash
 * Puabi
 * Ta-Nin
 * Urshanabi

Continuity

 * The Fourth Doctor gained knowledge of the Timewyrm when he was in the Matrix in DW: The Invasion of Time; he left a time-delayed message in the TARDIS for himself.
 * Ace still feels some of the after effects of the Cheetah Virus she became infected with in DW: Survival.
 * The Doctor consoles Enkidu (who believes he is the last of his kind) by telling him that another Neanderthal survives to the 19th century. (DW: Ghost Light)

Timeline

 * This story occurs after BFA: The Angel of Scutari
 * This story occurs before NA: Timewyrm: Exodus