StarCraft Episode IV

Introduction
At the end of StarCraft the Protoss hero Tassadar destroyed the Zerg Overmind on Aiur, with the help of the Terran hero, Jim Raynor. By using Dark Templar energy, Tassadar was able to completely destroy the Overmind, but at the cost of his own life.

Thus began the Brood War, as the Sarah Kerrigan, the Queen of Blades, battled with Daggoth for control of the Zerg.

Episode IV is something of an extension to Episode III, and the player continues the role of Protoss Executor.

The Retreat
The Zerg and Protoss were both left in a weakened state by the death of the Overmind and the battles on Aiur. The Zerg rampage mindlessly across Auir, killing 70% of Aiur's population, including the Protoss Conclave and it's once great fleets. At least two Zerg Broods were leaderless as a result of the Dark Templar Prelate Zeratul's actions.

With the Conclave eradicated, Judicator Aldaris, Praetor Fenix, Prelate Zeratul, and their human companion Captain James Raynor band together to unite and lead the scattered survivors. They appoint a new Praetor, Artanis. Convinced the Protoss were unable to further defend the Homeworld, Zeratul proposes evacuating Aiur. He will lead the Protoss refugees through the last Warp Gate on Aiur and to Shakuras, the world the Dark Templar had adopted as their own. The existence of this world came as something as a surprise to Aldaris, who was reluctant to evacuate, but Zeratul was able to convince him it was necessary. On their way to the gate, Zeratul and his companions meet with Jim Raynor and Fenix, who assisted in holding off the Zerg (who are attracted to any powerful source of psionic energy, such as the Warp Gate) until the Protoss can escape. Raynor and Fenix remain on Aiur to defend the Warp Gate. The Dark Templar never made an effort to defend their own side of the Warp Gate on Shakuras, a strange and dark planet, which would quickly cause problems.

The Dark Refuge
The refugees, now under the command of the young Protoss Praetor, Artanis, find a suitable site to create their new settlment. They did not immediately encounter any Dark Templar, who were not present around the Warp Gate and seemed to populate only pockets of the world. New Antioch was promptly attacked by Zerg, but were repelled by the Dark Templar, who had just arrived. The Zerg had taken control of the Warp Gate and could now infest this new world. The Dark Templar and Protoss refugees cooperated to destroy the Zerg who had nestled on the Shakuras side of the Warp Gate, then moved on to the primary Zerg Hive Clusters.

During the battle Jim Raynor and Fenix recaptured the Aiur side of the Warp Gate. They sent a transmission informing Artanis and Zeratul of this, and say they will shut down the Gate on their side to prevent any more Zerg from getting through. This will prevent the refugees and Dark Templar from sending any reinforcements to help Raynor and Fenix. Artanis, moved by this selfless act, promises to send as many troops as he can spare.

Zeratul has a reunion with Matriarch Raszagal, the Matriarch of the Dark Templar, in her Citadel at New Antioch, the main settlement of Shakuras. Zeratul had been away from Shakuras for "many decades".

Raszagal welcomes the Protoss refugees to her planet; she has no qualms with them now that the Protoss Conclave has been destroyed. She says there is a way to defeat the Zerg who have now spread over much of Shakuras. On her world lies another Temple which can harness the energies of the Templar and the Dark Templar to eradicate the Zerg. However, doing so will require the crystals Uraj and Khalis. The Uraj is a pure Templar crystal, while the Khalis uses the energies of the Dark Templar. In the meantime, two Zerg Cerebrates nestled themselves near the Temple, presumably in order to study it. The Zerg no longer appeared as insane as they had been after the death of the Zerg Overmind on Aiur. The Dark Templar, working with the refugees, defeat the Zerg and kill the two Cerebrates. They are surprised at the results.

Strange Alliances
A Zerg Overlord arrives, carrying Kerrigan. She informs the Protoss that she must talk with their Matriarch. The Protoss naturally protest, but Raszagal surprises them by agreeing to this discussion. Aldaris is especially upset at this.

In the Citadel, Kerrigan tells her story. She says that with the death of the Zerg Overmind she is now free of Zerg influence (at least the mental kind) but that this will soon change. There is a new Overmind growing on Char and when it becomes mature it will control her again. She claims that Daggoth ordered its formation from the merging of a many Cerebrates. Aldaris does not believe her and storms out of the meeting.

Zeratul is not particularly interested in assaulting the new Overmind. If he can acquire these two crystals and activate the Xel'Naga Temple, the Zerg will not threaten the Protoss on Shakuras. In some ways, it seems as if Zeratul is giving up on Aiur. Kerrigan, ever the diplomat, agrees to help the Protoss on their mission. Raszagal appreciates her help. Artanis, Zeratul, Kerrigan, and the Executor set off to find the crystals.

The Uraj is located on Braxis, an ice planet recently fortified by the Terran Dominion. The Terrans and Protoss forces (with Kerrigan aiding the Protoss directly) began fighting with each other, with the Protoss gaining a victory. Now they can establish a forward base to aid in their search. Artanis informs the Protoss that the Warp Matrix, the Protoss teleportation system, has been damaged and they cannot use the large Stargates to summon Protoss spacecraft.

Zeratul says that Braxis was a Protoss colony called Khyrador a long time ago, during the Aeon of Strife, and that the Uraj was abandoned on the planet with the chaos as the Aeon of Strife escalated. The Protoss had never returned to reclaim the crystal until now.

The Protoss find the Uraj. With Kerrigan leading the battle, the Terrans are defeated and the Uraj was recovered.

When the Protoss try to leave Braxis, however, they are surprised to find it blockaded by another Terran force. Vice Admiral Stukov introduces himself to the Protoss, demanding they surrender to the authority of the United Earth Directorate. The large orbital platform built around Braxis is studded with UED missile turrets, powered by fusion power generators. The Protoss had learned about Earth (and the UPL) from Raynor, and are quite surprised to find these humans here.

Artanis is dismissive of these Terrans, saying "What are they to such as we? Was it not we who defeated the dreaded Overmind?", but Zeratul counsels him, saying the Protoss were only able to defeat the Overmind with the aid of Terrans.

Artanis leads the charge against the Terrans, and with backup from Zeratul is able to destroy the fusion generators and cut a path to freedom.

Return to Char
The Khalis crystal is tracked to the planet Char, home of the new Zerg Overmind.

Zeratul had previously felt the energy of the Khalis on Char, which was, of course, heavily infested by the Zerg. The Khalis was next to a powerful source of psionic energy, which Kerrigan reveals is the new infant Overmind itself. Fortunately it is still weak, and this weakness extends to the Zerg who serve it.

Kerrigan suggests striking quickly and making off with the Khalis; it is curious that she doesn't take the opportunity to destroy the new Overmind immediately. Artanis suggests damaging the Overmind enough to temporarily subdue the Zerg, which Kerrigan says will also work.

Once the Protoss make their way to the planet, Kerrigan is able to use her formidable psionic powers to capture a small Zerg cluster which works alongside the Protoss. This combined force is able to retrieve the Khalis and escape. "the Khalis is ours!" exclaims Artanis "Let us depart this wretched world and return to Shakuras! ... Provided there is still a Shakuras to return to..."

An Old Enemy
When Artanis and Zeratul return to Shakuras, they find it in the throes of a revolt. Aldaris took control of a large number of Protoss refugees, including virtually all of the High Templar, Archons and Judicators, and led them in an attack against Raszagal. The Matriarch returned the favor.

Raszagal: "Executor, as Matriarch of the Dark Templar and custodian of this world, I hereby order you to terminate Judicator Aldaris, and quell this untimely uprising without delay! There will be no dissent among us while the Zerg are poised to strike!"

However, Zeratul had known Raszagal for a long time and felt that, perhaps, Aldaris was on to something. Out of Raszagal's earshot, he said to Artanis:

"There is something amiss here. The Matriarch has always been a wise and gentle soul. Though there is some merit in her decision, this is very unlike her."

Nonetheless, the Matriarch's forces attacked. Raszagal had even authorized the creation of the Dark Archon, something which had not been done for a thousand years (about the time the Dark Templar were exiled from Aiur). With this kind of power behind her, she was able to defeat Aldaris' revolt.

Cornered, Aldaris tried to explain himself to Artanis and Zeratul. He claimed that while the two Protoss were away, he discovered that Kerrigan had somehow corrupted the mind of Raszagal. Kerrigan interrupted his explanation by murdering him.

Only because of her assistance in acquiring the crystals did the Protoss let her leave, with a warning. Kerrigan retorted "Fine. I've done what I came here to do. I've insured the destruction of the renegade Cerebrates, and I used you to do it. Have fun, mighty Protoss... We'll be seeing each other again, real soon..."

Fury of the Xel'Naga
Matriarch Raszagal orders her warriors to take the Xel'Naga Temple, which is currently surrounded by Zerg, in order to activate it and use it against them.

Raszagal disturbs Zeratul with her next pronouncement: "The time has come to let loose the full fury of our powers! Never again shall Shakuras be despoiled by the foul touch of alien species! These Zerg shall be the first to fall before us!"

After Kerrigan's betrayal, Raszagal assured Zeratul that, with Kerrigan gone, she was back to normal. (Zeratul said that he had served her for millenia, which is impossible, as Zeratul is only 634 years old.) Now that the Protoss refugees sided once again with the Dark Templar, they could retake the Xel'Naga Temple.

Artanis carried the Uraj while Zeratul carried the Khalis. The Zerg were cleared from the Temple, which was surrounded by a powerful Protoss force. Artanis and Zeratul carried their crystals within the Temple and channeled energy through them into the Temple. The process took a long time (half an hour in the game), and the Zerg almost desperately began to attack the Temple. The Protoss were victorious, however, and when the Temple was about to activate, the Protoss forces withdrew from the temples and braced themselves for the upcoming attack.

The Temple created a giant burst of energy, seeming to kill all Zerg on the planet of Shakuras. As an additional surprise, the sun rose over the planet. Shakuras now had a night and day cycle like most other worlds... and the Protoss were confronted, once again, with the power of the Xel'Naga.

The Aftermath
The Protoss didn't dare reactivate the Warp Gate, fearing that Zerg would once again flood onto Shakuras. This had tragic consequences, since Zeratul could not warn Fenix and Raynor of Kerrigan's treachery.

The Protoss may be perfectly safe on Shakuras, provided they can activate the Xel'Naga Temple again. (The Temple was reactivated in StarCraft: Enslavers II but not in Drawing the Web.) The Terrans did not know their location. From there, they could threaten the Zerg on Char, especially their vulnerable Cerebrates. Indeed, this may have prevented the Zerg from conquering the entire sector.