History of Corridors of Time Part 1

Overview

Story mission on Mercury from Season of Dawn (quest "An Impossible Task", 850 Power). Using a Sundial time jump, the Guardian travels back to try to save Saint-14.

Walkthrough

1. Use the Perfect Paradox shotgun forged in the Infinite Forge to open the Sundial pathway.
2. Cross the Corridors of Time, defeating Vex along the way.
3. Arrive in Mercury's Dark Age at Zephyr Station, where Saint-14 is overwhelmed by Fallen of House of Rain.
4. Rescue him; the Ghost shows him a vision of the future Last City. The Guardian then returns to the present, timeline intact.

The quest chain is continued in Corridors of Time Part 2. The Corridors as a patrol space were open only briefly.