Grove of Ulan-Tan

Grove of Ulan-Tan was a Lost Sector in Echo Mesa on Io, reached through the Lost Oasis and guarded by Qeldron, Keeper. It was a private sector, normally inaccessible except during the Whisper quest. Its enemies are Vex and Taken. The route is mostly jumping puzzles, with moving walls that can push you into the abyss, a final room with mini-bosses before the main boss, and a 20-minute timer before players are returned to orbit.

Sources describe its chambers differently, from a short run of rooms to a longer path through a Vex Transfer Gate tied to the Vault of Glass, so a walkthrough is the best guide to the layout.

Whisper mission

The Whisper is a secret Exotic mission on Io. Its entrance is in the Lost Oasis: trigger a public event and kill a named Taken major, after which a Taken portal appears on a rocky structure near where the Taken Captain spawns. Entering it drops you into the Grove of Ulan-Tan. The quest is available weekly from Friday 10 AM PDT to Monday 10 AM PDT and rewards the Exotic sniper rifle Whisper of the Worm.

The Heroic version, which can be replayed after one completion, grants the Exotic Catalyst. Its five chests contain Blighted Essence, and a hidden sixth chest is found through an Oracle puzzle.

The Whisper was later removed and returned in Into the Light as a reprised mission, where the sector is called Taken Anomaly.