Upon completing the Diablo IV story campaign, players are met by a sentient tree called the Tree of Whispers. After speaking to the tree, players unlock the Whispers of the Dead questline, a repeatable endgame quest they can use to gain additional experience and obtain high-level gear. This is a brand-new mechanic in Diablo, so if you're having difficulty figuring it all out, don't worry; I've got you covered in this guide.
After beating the campaign and speaking with Lorath, a new Priority Quest marker will appear on the map in The Writhing Mire in Hawezar with a new Waypoint for The Tree of Whispers. Interact with the tree, and it will ask you to collect 10 Grim Favors from special quests called Whispers, indicated by red and pink icons on the map.
GameCrate/Diablo IV
Completing the marked quests will reward the player with Grim Favors -- the amount of which can be viewed by scrolling over the event on the map. Complete the Whispers to gain Grim Favors, and once you have 10 Grim Favors, you can return to the Tree of Whispers to select 1 of 3 Collection Caches that you can unlock for Legendary gear.
It's important to note that these quests have a timer that can expire but will refresh with new quests once the timer runs out. To check the progress of your Grim Favors, open the map and view the Whispers of the Dead Grim Favors bar at the bottom of the screen.
GameCrate/Diablo IV
The best caches are the Legendary Caches, as they have the best chance of dropping the most Legendary Items. However -- regular caches can also contain Legendaries. Caches from the Tree of Whispers can include all pieces of wearable equipment. They also include gems, gold, herbs, ore, and a variety of other items.
Whisper Quests in Diablo IV
There are various Whisper Quests in Diablo IV, each reflecting other events and missions you've probably already completed. The Whisper Quests in Diablo IV include:
Dungeons: The typical dungeon involves completing a series of tasks, then taking on a dungeon boss. If you haven't completed the dungeon before, it will unlock an Aspect you can use.
Local/World Events: These are the typical events outlined with an orange quest marker in the game. You'll need to complete the objectives in the allotted time. You'll also get some Obols for your trouble in most cases.
Assassination Quests: Players must travel to a specific location, interact with a corpse, then defeat an enemy to gain Grim Favors.
PvP: Players can enter PvP areas and take down bosses to gain Grim Favors. They can also collect Seeds of Hatred that they can then bank at Altars of Extraction to gain powerful items.
Rituals: In these events, players must travel to set location markers and interact with in-game entities to Invoke rituals and complete the task.
Harvest Events: Players must harvest a certain resource in a select area. Once they reach the cap, they'll be rewarded with Grim Favors. Typically this involves killing mobs.
The Tree of Whispers is a powerful endgame entity in Diablo IV. Elias, one of the antagonists in the game, has his head mounted there, along with other characters from the lore of the game. While its origins remain somewhat elusive, it does provide fun daily activities players can complete to get really good gear.