|Description||You completed all missions after the prologue without alerting anyone.|
How to Acquire Edit
As the achievement/trophy states, Corvo must stay completely hidden after the prologue. This can prove difficult, as such, the best plan of action is for Corvo to take alternative paths and utilize Sleep Darts and Blink to avoid enemies that cannot be passed normally.
The achievement also states that the main targets of the game must be unaware of Corvo's presence, making the stealthy approach the only option.