The Dungeons of Dalaran

The Dungeons of Dalaran is chapter 3 of Curse of the Blood Elves. It occurred hours after A Dark Covenant. Prince Kael'thas Sunstrider and his followers had been arrested by the forces of Lord Garithos for allying themselves with the Naga, despite the fact that without their aid, Kael and the blood elves would've been destroyed by Dalvengyr and the Scourge.

First stage
Vashj broke Kael out of his magical prison, were he was held and awaiting execution. Together they released Kael's lieutenants, as well as some of his forces, which not only had to face the Dungeon's jailors, but also creatures once kept by the Kirin Tor for experimentation and the ghosts of the Archmages killed by Arthas during the Siege of Dalaran.

Kael and Vashj were forced to kill Kassan, the Dungeons' warden and an old friend of Kael, in order to reach a dimensional portal, the one opened by Kel'thuzad to release the Burning Legion, and scape to Outland but to do that they needed to buy time holding Garithos at bay while the Blood Elves scaped through the portal.