The Whistle in the Dark is part of the string of weekly new weapons added to Fallout 76. As was the case with its predecessors, obtaining it requires completing a set of five Survival mode challenges.
Three of the five challenges required for unlocking the Whistle in the Dark weapon ask you to perform certain actions during night-time. In Fallout 76 that's between 6 PM and 6 AM.
Whistle in the Dark Weapon
Two of the night-time challenges required for getting the Whistle in the Dark weapon in Fallout 76 involve tasks you're already very familiar with, one requiring you to pick a lock, the other to hack a terminal. Both locks and terminals are commonly found across Appalachia, the nuclear silos and Watoga being two locations you're very likely to find some.
The third night-time challenge for unlocking the Whistle in the Dark tasks you with taking a photo of a human-like creature. All you need to do is ready your camera and find a Super Mutant, Scorched or Ghoul roaming the Wasteland. Snap a photo and you've two challenges left.
You can use the star of your photograph to complete the next challenge as well, provided you've a Stealth Boy on you. Simply use the Stealth Boy, creep up behind any creature in Fallout 76 and kill it. The last step on the path to obtaining the Whistle in the Dark requires that you destroy a turret while sneaking. The ideal way to complete this final challenge is heading to a relay tower, crouching and shooting a turret mounted on its wall.
The Whistle in the Dark weapon is a legendary assault rifle that grants +1 Perception and +33% V.A.T.S. accuracy during the night.
Fallout 76 is out now on PC, Xbox One and PS4.