When an D2R Ladder player arrives at the auction, proceedings are D2R Items disrupted by an attack that they have to fight. In the course of fighting the fetish group are able to steal the necklace and bring it back to the hideout; which is to East of the auction. The player must go into this hideout and smash the necklace.

This quest is accessible on any map available in the game, and starts by trying to unlock a treasure chest. If you attempt to open these chests, the player is attacked by spirits. When these spirits are defeated, it breaks the curse that is placed upon the chest, allowing the player to reach the contents. 

It is imperative that players act as fast as possible in fighting the attacking spirits. If the player defeats them swiftly enough they will be rewarded by two treasure chests. These spirits aren't too difficult to defeat, even though they spread out and shoot out magical projectiles to the player.

This is about as hidden as side missions can be on D2R Ladder. There is no indication that "Ambush" is close to being activated, and it can happen at any time in the game. This quest begins when a crowd of hostiles suddenly pop up around the player and immediately attack. 

The type of enemy determined by the map the player is on, and these ambush groups will contain elite enemies. The goal is to stop those enemies trying to ambush the player. The quest list displayed on the left side of the screen will show the player the enemies need to be defeated to Diablo 2 Resurrected Ladder Items finish the quest.