The Prologue is the first available zone to the player. It is where the player's starting units are unlocked, and where the tutorial battles take place. There is no Starpower requirement for this zone.
Units unlocked here
As a battleground
The Prologue is known as Twin Temples I when selected as the map for a battle. The map is relatively clear of any mountains or gaps, except a single mountain in the middle of the map.
Extractor and SENSO-Gate locations
Each players' SENSO-Gate are located on the opposite corners of the map. For each player, one Extractor is near the SENSO-Gate, the other one farther away.