The haze has been lifted. I can see as clearly now as the day that I plunged the Ashbringer into my own heart to free my father's cursed soul: my last memory as a free man.
We must take back Acherus from the Scourge if our order is to survive in this new world. I have taught you how to call forth a death gate. The death gate will return you to Acherus when you call upon it, <name>. The first battle of the Knights of the Ebon Blade is underway! Death to the Scourge!
Completion
The Lich King has returned to Northrend, wounded by the Ashbringer, but the second floor still holds the last of his armies.
Notes
Stepping through the Death Gate will take you out of the instance and into the main world. The lands below Acherus are now the Ruins of the Scarlet Enclave, and everything has been destroyed. The plague cauldron is still there but you can no longer get Noth's Special Brew from it, and the pumpkins have been transformed into indescribably hideous things that look like they are breathing. The ground soil is now puke green colored, the trees are now brown and decaying, and the skies are filled with the same noxious reddish-orange mist as in the rest of the Eastern Plaguelands.
If you manually walk back to Death's Breach, you will remain in the instanced version of the Plaguelands until you use a Death Gate, and Acherus is completely empty save for a few trainers. This is an expected issue given that the battle for Acherus takes place in the non-instanced Acherus, but it is somewhat funny.