Starcraft 2, Brutal difficulty walkthrough with commentary
Mission 15: Ghost of a Chance
Much like the first Zeratul mission, you must solve a series of puzzles using a special hero unit (Nova) and a bunch of regular units. You choose between this mission or Breakout (not to be confused with the zombie level Outbreak). If you do Outbreak, you get Spectres, while this mission gives you Ghosts. This mission requires a bit of fine unit control, but nothing special. Breakout is actually easier.
Starcraft 2 Mission 15: Ghost of a Chance walkthrough on Brutal (w/commentary) Part 1 of 2
Starcraft 2 Mission 15: Ghost of a Chance walkthrough on Brutal (w/commentary) Part 2 of 2