WoWDB

Coilfang Reservoir: The Slave Pens makes its return to current content via the Timewalking system introduced with Patch 6.2.  All players level 71 and above will be able to queue for the Timewalking version using the LFD tool when the special event is active.  The official highlights blog is here.  Don't forget to pick up A Burning Path Through Time.

And for the love of all that's good - or at the very least not make your healer believe you are only counted amongst humanity as a kindness to your mother - kill the trash pack, free the prisoner, deal with the summoned trash pack, and then speak to the freed prisoner for +110 buff to nature resistance and +5% to all stats.  Quagmirran has a mean acid attack.  Your item level will not protect you if you fail to dodge (which does happen more often than one would think; keep reading).

Also, don't engage the boss while in the water.  Characters move slower when swimming, so chances are the tank and/or the melee DPS won't be able to dodge the acid that remains on the environment until the boss is defeated.