Increases your Field of View by 9/12/15 °.
Field of View gains do not stack

Survivors within your Terror Radius suffer from inefficiency:

When using an Item, its Depletion rate is increased by 80/90/100 percent.

The Auras of regressing Generators are highlighted in white.

If the Regression progress is interrupted on a Generator, its Aura will be highlighted in yellow for 8/12/16 seconds.
Surveillance increases the audible range of Survivors Generator-repairing noises by 8 meters.

You become obsesses with one Survivor.  When your obsession is hooked, Furtive Chase receives a token, up to a maximum of 4 tokens.

Each token decreases your Terror Radius by 4 meters while in a chase.

When a Survivor rescues the Obsession from a hook, the rescuer becomes the Obsession.