In Utter Darkness

In Utter Darkness is a mission in the protoss mini-campaign in StarCraft II: Wings of Liberty. It is a flashforward of the Overmind's vision as seen by Zeratul, and watched by Jim Raynor on board Hyperion.

Observing the Future
Zeratul witnessed the protoss gathered for a final stand against the Dark Voice, in a future where Infested Kerrigan was dead. It was a vision from the Overmind channeled to Zeratul by Tassadar.

The Last Stand
The protoss gathered their remaining strength for a last stand against the Dark Voice's combined hybrid and zerg force. The besieged hoped to survive long enough to complete an archive. The archive was intended to aid those who might arise after and challenge the Dark Voice.

The protoss were finally wiped out. They were followed into extinction by the zerg.

Gameplay
Players control a protoss army, including a number of heroes, besieged by hybrids and zerg on three sides. The main objective is to kill a certain number of enemy units. The target for casual and normal is 1500. After that, the mission continues until the protoss are wiped out.

Players also receive a benefit for defending the archive for 20 minutes.

Strategy
The mission requires the constant replacement of casualties, and the economy to sustain this. Resource gathering will likely gather minerals faster than units can be produced; the minerals may be used to construct photon cannons at the bridges, and later on the upper plateau. There is a rich mineral field expansion in the north-west, and taking advantage of it while opposition is still weak will provide a great long-term advantage; however, it is perilously close to the zerg spawn point there and an active army along with photon cannons will be needed to defend it. Against such high odds, do not neglect the upgrades at the forge and cybernetics core. Several warp gates to quickly create reinforcements at a chokepoint are useful: zealots in particular are cheap and hardy for their cost, and if nothing else provide distractions for enemies to protect more costly and valuable units.

If the archives are to be saved, the first part of the battle must be fought on the lower ground. Reinforce the bridges early with photon cannons. A mixture of units may be used to hold the choke points. Colossi may take the high ground, with immortals in the breach to absorb attacks, while contribute Psionic Storm from then rear. Once the archives are complete, it may be advantageous to fall back to the plateau and defend the two ramps instead.

Reinforcements arrive over time; each reinforcement wave features a certain type of unit led by a related hero unit. These waves are usually best grouped separately rather than into one large attack group. This allows a tailored response to specific threats, especially as attacks are not always symmetrical. Urun and the phoenixes may counter mutalisks and brood lords, and use Graviton Beam on the hybrids that appear later. Mohandar and the void rays together form an effective anti-hybrid force. The carriers may be doled out to reinforce the choke points. Zeratul's Void Prison is effective for immobilizing ultralisks who are immune to graviton beam.

Artanis' mothership has the Vortex ability, which disables and makes invulnerable units in an area for a short time. Use it to temporarily halt an enemy swarm. If a force of units is being overwhelmed, using recall to save them is a good idea, especially near the end of the mission when the base is likely to be overwhelmed and every defender counts.

Once resources are mined out, use probes to draw enemy fire. If there is difficulty making the kill count as the end nears, or if the goal is the achievements, aim for zerglings.

A simple and effective, though expensive strategy is to line the bridges with dark templar set to "hold position", preventing the zerg and hybrid forces from entering the base and allowing the dark templar to slowly but surely cut them to shreds. The enemy forces will not be able to see and attack the dark templar without an overseer present - if the player keeps an eye out for overseers and kills them with void rays and/or phoenix before they come close enough to spot the dark templar, this sort of barricade is utterly impenetrable. You will, however, need to remain extra vigilant against the coming waves of banelings later on due to their ability to decimate your walls of dark templar swiftly regardless of their invisibility.