Splinter Cell: Extinction started as a pretext for the people from Companion Pictures to test night filming with their new camera. However, the universally positive reception of the ten-minute "prologue" (uploaded to Youtube and then posted on most major gaming websites) and the "To Be Continued" line at the end caused the studio to create more episodes.
The prologue opens with the titular Splinter Cell: field agent known as Corbin and two-person Mission Control, computer tech Arra Welker and intelligence analyst Danny Bryson, attempt to capture the man known as Desmond. However, as soon as Corbin detains Desmond, the plan changes and Corbin is forced to escape the ambush, apparently plotted with the full knowledge and assistance of Desmond.
Three months later, it turns out that Corbin wasn't the only one Third Echelon field agent to be ambushed this way: all of them, except Sam Fisher, Corbin and Julian Hunter, were killed. One of the handlers, a woman named Bryn, enlists Corbin's help to rescue Hunter after he was kidnapped by members of the conspiracy.
This series provides examples of:
- Action Girl: Bryn. In episode 6, she outmaneuvers a whole team of mooks sent to ambush her. Almost.
- Big Applesauce: The series are set in New York.
- Black Dude Dies First: The double agent who tries to free Arra from Third Echelon. And, from the main cast, Dominic.
- Cliffhanger: Setting up a Clear My Name plot for season two.
- Darkened Building Shootout: After Arra shuts down power in the building.
- Distressed Dude: Hunter.
- The Dragon: Desmond Solvern, to director Ward.
- Expy: Corbin for Sam Fisher, Arra (and, even more, Bryn) for Grimsdottir, Director Ward for Director Reed and Douglas Hyland for Douglas Shetland. Corbin is noticeably snarkier and more French than Fisher, though.
- Eyepatch of Power: In the prologue, Corbin uses a nightvision headset similar to the ones used by Archer and Kestrel in Conviction. Similar headsets are used by 3E Splinter Cells in later episodes.
- Glasses Pull: Used by Desmond to signify that he was only playing a harmless geek. Then he puts his tactical vest on.
- HeelFace Turn: Hunter. Nothing says "You're fired" like a shot in the back.
- Hollywood Silencer: Not only it does the familiar whistling sound, it's just as big as a compensator.
- How We Got Here: "47 minutes from now".
- Made of Iron: In the prologue, Corbin performs a dynamic exit after being sedated and shot in the stomach. At least for the sedative, he took an antidote. And once he flees the building in episode 1, he grabs a first aid kit.
- Bryn survives a similar wound in episode 6. And she doesn't even need a first aid kit.
- Magic Antidote: In three seconds from reaching for the antidote to Arra turning the lights out, Corbin goes from noticeably woozy back to killing machine.
- Mission Control: Arra in the prologue, Bryn in episode 3.
- Mythology Gag: Sam Fisher is mentioned as a 3E operator gone missing in the 2nd episode.
- In episodes 4 and 5, Corbin performs a half-split to get the drop on the opponents below (who, of course, don't look up).
- In episode 5, Corbin uses a fiber-cam to look under a door.
- See Eyepatch of Power. Corbin himself uses three-lensed goggles in the series.
- The Mole: Hunter, starting with the 4th episode and going into full swing in the 5th.
- Never Found the Body: Julian Hunter, in episode 7. He gets better. Apparently director Ward does as well in the finale.
- Non-Action Guy: Nathan Shay is an evil example.
- One-Woman Wail: Used when Corbin walks into the ambush. The music goes silent, then floodlights turn on in synch with an orchestral "wham", followed by a One Woman Wail and Sad Strings.
- Only One Name: Corbin. In the prologue, also Desmond.
- Private Military Contractors: Cutwater, the company hired by director Ward. Any relation to the infamous Blackwater is fully justified, as of episode 3.
- Sharp-Dressed Man: Director Ward.
- She Will Come for Me: The reason why Arra is kept alive by director Ward - to lure Corbin out.
- Shout-Out: Headset scene in episode 2 is a homage to a similar one in Splinter Cell: Conviction.
- Spell My Name with an "S": after seven episodes, the creators finally specified that it's "Bryn", despite various characters pronouncing it "Brin" or "Bren".
- Spoiler Opening: Hunter leaning out of the chopper, spoiling the season 1 finale.
- Take My Hand: Hunter, when Corbin has to get off the speeding boat in episode 8. Having his reasons not to trust Hunter, Corbin leaps and grabs the helicopter's skids instead.
- Unexplained Recovery: Bryn. With a Series Continuity Error on top.
- You Have Outlived Your Usefulness: Douglas Hyland and Julian Hunter.