The Night Elves had, of course, called for aid from more than just the Horde. The Alliance had received their plea for help, but couldn't afford to give up the perfect opportunity to reclaim lost territory. So the Alliance sent only a limited number of reinforcements, led by Jaina Proudmoore, the daughter of Admiral Daelin and a brilliant mage. They set sail for Kalimdor aboard Kul Tiras's fastest ships.
Since the Alliance had no foothold in Kalimdor, the Night Elves set aside a plot of land in their territory so the Alliance could build a base. Jaina didn't refuse, of course. After all, it was something the Alliance hoped to gain by sending troops, but couldn't openly ask for.
While she had her people build the base, which was named Theramore, Jaina began marching toward Astranaar. It was the only place with a portal to Mount Hyjal.
The army needed time to mobilize and assemble. To shore up the defenses at Mount Hyjal, Leiluo first sent Illidan ahead to Astranaar with five thousand soldiers. Malfurion had planned to return with Leiluo, but when he saw Illidan heading back, he couldn't sit still. Leaving the delegation behind, he went with Illidan and returned to Astranaar ahead of the others.
As he "looked" at the familiar scenery around him, Illidan was filled with emotion. Time might have changed the landscape, but a Demon Hunter could see the unique energy of the place clearly, even through blind eyes. As Illidan and his party drew closer to Astranaar, his restless heart inexplicably settled. Even when he finally "saw" the familiar figure on the city walls, he remained unruffled.
Tyrande, on the other hand, struggled to contain herself when she saw Illidan. If Malfurion hadn't suddenly stepped beside her, who knew what she might have