Warcraft 3. The Beginning of World Of Warcraft

Human Campaign: The Scourge of Lordaeron

Prince Arthas, a paladin of the Silver Hand, the Captain and Jaina Proudmoore, Arthas' former lover and apprentice-Archmage, are investigating a strange plague that is spreading across the lands of Lordaeron. To their horror, they find that the plague turns unsuspecting people into hideous Undead warriors, and must move to stop the Undead's plans. Arthas proceeds to hunt down the plague's originator: Mal'Ganis. Mal'Ganis travels northward to the icy lands of Northrend, and Arthas follows him. There he aids an old friend, Muradin Bronzebeard, who tells him of a power weapon, a sword called Frostmourne. Arthas obtains Frostmourne, at the cost of Muradin's life, and uses it to defeat Mal'Ganis. However as a result, Frostmourne steals Arthas’ soul and turns to ally the undead.

Undead Campaign: Path of the Damned

With their new leader, the Undead must move to complete their purpose in Lordaeron, which is to destroy the remnants of the Alliance, and to pave the way for a new invasion. In a series of quests, Arthas succeeds in reviving a former adversary, Kel'Thuzad, as a Lich, and the two successfully open an inter-dimensional portal for the true masters of the Scourge, the Burning Legion, to enter the realm of Azeroth.

Orcish Campaign: The Invasion of Kalimdor

After escaping Human captivity and fleeing to the shores of Kalimdor, Orcish warchief Thrall must lead his brethren to safety and ensure their survival in this strange and hostile land. Help comes from the Tauren, a nomadic group of Kalimdor-natives, and their leader, Cairne Bloodhoof. Unfortunately, fellow Orc Grom Hellscream falls under demonic corruption, and Thrall is forced to ally himself with Jaina Proudmore, now leader of the survivors of Lordearon. He also discovers (courtesy of an oracle) that his fate is to help repel the Burning Legion, and he and Jaina accomplish this goal, and also to save Hellscream. Afterwards, Grom insists upon battling Mannoroth, the demon who cast him into the corruption. Thrall and Grom succeed in vanquishing Mannoroth, but Grom is slain in the proccess.

Night Elf Campaign: Eternity's End

With the coming of the Undead and Burning Legion as well as the Humans and Orcs, Tyrande Whisperwind and her Night Elf Sentinels fight a desperate battle to save their beloved home of Kalimdor. She first reawakens her lover, Malfurion Stormrage, and then the Druids of the Talon and finally the Druids of the Claw. She also decides to free the great betrayer, Illidan Stormrage, and he is eventually instrumental in weakening the Legion. Finally, she and Furion join forces with Proudmoore and Thrall to delay the Legion's advance until a proper end can be arranged for their leader Archimonde.

When Queen Azshara finally decided to make the naga's existence known, she sent Lady Vashj to establish contact with the surface dwellers. Lady Vashj met the demon-cursed Illidan and they struck a pact to aid each other against their night elf enemies.MoM 189 Vashj and her people were quick to join him, and their first act of loyalty was to facilitate Illidan's escape from Kalimdor, and bring him to the Broken Isles and the Tomb of Sargeras.

But the naga knew that Maiev the Watcher would be quick to follow, and so Vashj rallied her forces and battled the night elf's forces as they made their way to the Tomb, where Illidan and Vashj then stole away into its ancient corridors. When Maiev confronted Vashj, the Sea Witch told Maiev that her justice had no place there, and when the Warden demanded how she would know anything of the night elven way, Vashj replied by telling that the naga were night elves once. Then she slithered off to join Illidan in the Eye Chamber. Illidan used the Eye of Sargeras to collapse the Tomb, and then escaped. Vashj took the majority of the naga to Lordaeron to make preparations for the next phase of their plan while Illidan and some servitors remained behind to deal with Maiev for good.

After careful observation, Vashj saw that Kael'thas, prince of the ruined Quel'Thalas, was the perfect new recruit for the new order Illidan was fashioning. And with the ample forces Maiev had brought to Outland, Vashj knew that they would need reinforcements. Kael had been under the oppressive whip of a racist human general named Garithos, who had sent Kael and his people on missions that any laymen could do while keeping the elves from the front lines. Kael first encountered Vashj when he found his shipyard ruined, and thus his means across the river scuttled. She approached him with an offer of assistance. Kael was hesitant, having fought the naga alongside Maiev at Dalaran, but Vashj insisted, and Kael accepted. Vashj watched Garithos' rage at Kael's dealings with her. But Garithos then sent Kael and his elves against an invading force of undead. Kael was eager to prove himself in battle, but Garithos recalled Kael's support, siege, and cavalry units to the front lines, leaving Kael with a very meager standing force.

Vashj felt that the time was ripe to intervene, and so offered her troops to strengthen his own. Kael was again hesitant, but Vashj insisted that it was better to survive than obey the word of a rash tyrant. Together they defeated the undead forces and retook their bases. When Garithos approached, Kael ushered Vashj away, saying he could not assure her safety. She did, but watched as Kael and his people were taken away in shackles supposedly for betraying the Alliance by siding with the naga. Vashj infiltrated the Dungeons of Dalaran through the sewer system and found Kael, killed his guards, and freed him. Vashj told Kael that escape was possible through the remains of the gate Kel'Thuzad had erected to summon Archimonde. She helped Kael escape the jails and destroy Kassan's forces, robbing valuable items from the magical stores as they went, and freeing his people from their cells. Upon reaching the streets, however, Garithos proceeded to assault the portal with his forces. Vashj, Kael, and some blood elf engineers raced to build defensive structures to stop them before they reached the portal. After a perilous battle, however, they were victorious and fled through the portal to Outland.

When they came through the portal to the shattered landscape of Outland, Vashj explained that it was once the homeworld of the orcs, but the Cataclysm had turned it into the barren, broken waste it now was, and that Illidan was somewhere waiting for them. Vashj and Kael searched fruitlessly for days, until Vashj caught a familiar scent on the wind. Illidan had been captured by Maiev and was being hauled back to her base in a magical prison wagon. Vashj and Kael battled Maiev for dominance, but finally reclaimed the wagon and brought it back to their base, where Illidan was freed. Illidan thanked Vashj for her loyalty, but Vashj gave credit to Kael. Illidan then told them of his plan to rule Outland by overthrowing the current ruler Magtheridon.

And so Vashj and Kael defended Illidan as he closed the dimensional gates which supplied Magtheridon with his reinforcements. After they were all successfully closed, Illidan's armies marched on the Black Temple. Vashj and her naga infiltrated the aqueducts and attacked the Black Temple from a side entrance, as Akama and his Broken destroyed the automated defenses. Vashj was responsible for killing the Mistress of Torment with aid from only a few myrmidons and snap dragons for support. Eventually, they battled their way to Magtheridon, and in a titanic battle, defeated him.

But Kil'jaeden appeared, and mocked their foolhardy attempt to betray him. He then commanded that they find the Frozen Throne and destroy it.

Vashj, Kael, and Illidan went back to Azeroth and advanced upon Northrend, only to be met at every turn by Arthas and Anub'arak, Ner'zhul's prime generals. Finally, they reached the Frozen Throne, and the forces squared off against one another. But, in the end, Arthas opened the doors to the Throne Chamber. Illidan was there to greet him, and the two battled on the face of Icecrown. After a short fight, Arthas defeated Illidan.