Star of Treznat: Mission 1 - Clean Slate (official title and title in starcraft 2 multiplayer custom games)
For the this introductory mission, you play as an anonymous commander of a small Dominion infiltration force including the ghost Echo. Several abnormal readings including factory emissions and psionic emanations from the planet Ynoth have finally worried Mengsk. He sends in your team to check it out.
This map is currently only available under the custom game sections in multiplayer of Starcraft 2. The download version is coming soon. Mission 2 is currently being worked on, this mission took me two days (which does not prove it is bad!), so expect new missions quickly!