From Destinypedia, the Destiny wiki
Guardians must lead an assault into a Taken lair within The Sludge, led by Vendraxis, Shadow of Oryx. Sometime after reclaiming the Last City and finding the legendary Warlock Osiris, it was used as an arena in which the Guardian was tasked by Commander Zavala and the mysterious Ana Bray with liberating a shard of the Traveller to use as bait against the Hive god Xol and its servant Nokris. After a lengthy firefight with the resident Taken, Ana Bray, with the help of the last Warmind, Rasputin, freed the shard from its Taken vices and returned to Mars.
List of appearances