In this series, the story finds an older Sam Fisher living in isolation in rural Poland, having left the world of espionage behind. His quiet life is interrupted when a young operative (Zinnia McKenna) arrives wounded at his farmhouse, having barely escaped a botched mission in Lithuania where her partner was killed. She brings evidence of a global threat linked to an antagonist family from one of the games (you know, I forget which one because it's been so long! I need to reply the originals...but I digress). 

The primary conflict revolves around Displace International, the private military company previously run by Douglas Shetland, which is now under the control of his children, Diana and Charlie Shetland. Diana publicly pitches the company's new "Xanadu" project as a world-saving green energy solution to European leaders, while secretly using a highly dangerous "Chaos Particle" algorithm to manipulate global power grids and create an energy crisis for profit.  Pulled back into action, Fisher mentors McKenna as they work alongside his old colleague Grim (Anna Grímsdóttir) and Fourth Echelon, who provide remote tech support after their systems are initially hacked. The pair race across Europe, infiltrating various locations to uncover and stop Diana's plot. 

In the final episodes, Sam and McKenna track the villain's gas-carrying ship, the Lazarev, to an island called Xanadu, where Diana is hosting a summit for Europe's elite. In a twist, Charlie, Diana's half-brother, has his own agenda; he hacks the ship's controls, redirecting it to collide with the island and kill all attendees, including his sister, to create a massive power vacuum he can exploit.  Sam and McKenna manage to escape the ship just before the collision, powerless to stop Charlie's catastrophic plan, which succeeds. In the aftermath, Charlie seems determined to take over the new European energy market. The season ends with Sam tracking down Charlie in his office and, off-screen, presumably killing him.