The subject of this article appeared in Call of Duty: Black Ops III. The subject of this article appeared in Zombies mode

Sanguine Serum is an achievement/trophy in Call of Duty: Black Ops III. It requires the player to drink "fresh" Widow's Wine.

To achieve this, the KT-4 must be built and equipped as the location is hidden behind the neon blue webbing behind Lab A, beside one of the Perk Machine spawns and the location of the "Blue" tinted water. Shooting the web will dissolve it and open the pathway into the nest of the Giant Spider which will crawl out of its lair and attack.

Upon the death of it, A minor cave-in will occur and drop down some rocks to create a passage across the crevasse that was between the entrance and the deeper parts of the cave. Deeper in is a pump system with the Widow's Wine logo on it, draining liquid from a pool. Interacting with this pool will give the player Widow's Wine for free if they have the Perk Slot for it and awarding the achievement. The pool remains open for the remainder of the match.

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