S3: Silent Storm - Sentinels is an add-on for the turn-based combat strategy game S2: Silent Storm which took place during WWII and featured 3D fully destructible environment, rag-doll physics and non-linear gameplay. Sentinels also has the same features but with enhanced enemy AI, new missions and weapons.

The plot takes place right after WWII where you try to destroy the remnants of the terrorist organization Thor's Hammer which was also our target in S2: Silent Storm. But now instead of soldiers, we control the mercenaries of a counter-terrorist organization in Sentinels which both features historic and science-fiction elements..