Scout Vestige Part A
Location: Depths – Silent White
From the mistle take the east path (left most path with a locked door behind you). When the path opens up, take the stairs on the right up, passing a car half-buried in some rubble, then descending down another set of stairs. Follow the path forward until you see a lantern on the ground. Take a right to find the vestige on the ground near some busted up cylinder containers.
Scout Vestige Part B
Location: Depths – Misty Ruins
This vestige is located at the end of the southeastern path behind a delivery truck to the left of the path leading to a boss. Approaching the vestige will trigger a Trial of Blood.
Scout Vestige Part C
Location: Depths – Arachnid Grotto
From the mistle take the path heading south. When you emerge from the path into the big cavern room keep heading straight to find this vestige at the end of the path.
Scout Vestige Part D
Location: Depths – Zero District
This vestige is located on the ground next to a set of stairs. To reach it, follow the path south of the mistle. The stairs will be located to the left of the path leading to the boss area.