Zero Hour

"I been in plenty of hold-outs before... Not against the zerg, you ain't."

- Tychus Findlay and Jim Raynor discuss the upcoming battle.

Zero Hour is the the third terran mission of StarCraft II: Wings of Liberty.

Raynor's Raiders prepared to leave Mar Sara with the "liberated" alien artifact. However, they were suddenly besieged by invading zerg. The rebels held out until Hyperion evacuated them.

Background
The stolen alien artifact was transported by truck back to Backwater Station. The trip was uneventful despite fears of Dominion pursuers. The Raiders' timing was impeccable. As they neared Backwater during the night, zerg spores began landing at the abandoned dig site. The infestation spread rapidly to the outskirts of Backwater within an hour. Pockets of Mar Sara Separatist troops desperately held out in hope of relief.

The Raiders immediately requested support and evacuation from their mobile base and headquarters, the battlecruiser Hyperion. For the second time in five years, Jim Raynor was fleeing Mar Sara in the face of a zerg invasion.

An Old Familiar Feeling
The Raiders were entrenched in a defensible position accessible from the ground by only two bridges. The rebels received regular appeals for help from terrans in the area. The zerg attacked from nearby nests and were reinforced by sacs and nydus worms.

As dawn broke, the zerg made a final large scale push. The Raiders were saved by the timely arrival of Hyperion. The ship finished re-entering the atmosphere nearby and blunted the immediate threat with its weapons. The Raiders had boarded by 06:21.

Escape from Mar Sara
Hyperion fought through mutalisks to make the warp jump from within the atmosphere. To his horror, Raynor learned the zerg attack was part of a larger, sector-wide invasion. The Queen of Blades was on the move. The Second Great War had begun. Jim Raynor received a distress call from Agria, but was also given a lead on a job by Tychus Findlay. The Raiders could take one job, leaving the other for later.

Conversations after Mission

 * Main article: Campaign quotations''

Gameplay & video walkthrough
A strong defense is required to finish the mission. On lower difficulties, place two or three bunkers at each entrance, supported by two or three SCV by each. Build missile turrets along the chasm to ward off mutalisks. On casual difficulty, engineering bays and missile turrets may not be built.

Neutral buildings outside the base provide vision. These are destroyed by the zerg on hard or brutal difficulty levels. Occasionally, trapped militia forces consisting of marines and medics request help. Once rescued, they come under player's control.

On hard or brutal difficulty levels, the enemy is better equipped and more aggressive, requiring stronger defenses. Enemy receives armor and weapons upgrades, sends roaches (and banelings on brutal) against the player, expands creep across the map and moves spine crawlers forward, and periodically bombards the player's base with sacs that release zerglings and creep tumors.

Several dozen marines and at least eight medics are required to unlock the achievement of destroying four hatcheries on hard difficulty level. When attacking zerg bases up ramps, move the marines up several steps to allow marines in the rear to fire.



Development
The following achievement was removed during development.

On the BlizzCon 08 version of the "Escape from Mar Sara" cinematic, Matt Horner updates Jim Raynor of the situation while the Hyperion is still travelling through warp space.