The French ambassador Pierre Simon and his family are travelling from Saint Petersburg to Paris aboard the Blue Harvest, a military NATO-developed train, when it is hijacked by terrorists known as the Knights of the Apocalypse. Negotiations yield no result and the only hope is lieutenant Jack Morton, part of the original escort, who manages to sneak back on the train. His job is to take back control of the armoured train, stop the terrorists from deploying a nuclear weapon and rescue the hostages.
Covert Ops: Nuclear Dawn is played as a third-person shooter, but also introduces stealth elements, puzzle-solving and driving sequences with the train. The different compartments of the train form the levels. Next to regular movement, Jack can dash and use a search function that allows him to peek around corners and into rooms. Morton is in touch with the headquarters and also collects information about the organization on his way. The game uses an intelligent targeting system where the cross-hair changes colour based on the viewing angle. Shooting from a difficult position will do little damage, while open shots have a larger chance of hitting enemies.
The futuristic external shape of the armored train "Blue Harvest," -- and its speed of several hundred kilometers per hour compared with normal trains -- make it fairly obvious that Blue Harvest is imagined as a maglev (magnetic levitation) train. In other words, Blue Harvest is supposed to be a militarized version of something like Japan's several shinkansen (新幹線) "bullet trains," France's TGV which is an abbreviation of train à grande vitesse (high speed train), or the new commuter maglevs that are now being run by Amtrak®.
The terrorist group in the game was called "The Army of the New Revelation" during development.