Nobody has ever heard of ODIN. ODIN is about as secret as a government agency can get. Because within ODIN there is General Operations, which speaks for itself; ODIN 5i, which deals with intelligence gathering; and then there is ODIN 1i, which deals in operations so sensitive not even the CIA can touch them. All three are run with an iron first by The Chief, a giant with a gigantic IQ. His top agent is Alex Mason. But when an ODIN 5i agent based at the US Embassy in Manila goes missing and his encrypted laptop disappears with him, the whole ODIN structure is put in peril.

A master assassin craves one thing above all else: a normal everyday life. Trained to be a killer from the age of 11, Peter has never known the things the average person takes for granted. He has always been an asset. Burned by the CIA and now occupying their secret hit list, he works overseas as a Ronin, living a solitary life in hiding. But someone knows where he is. A strange man arrives at his door offering Peter the chance of a real life. "Get this done and you can be free," he is told.

Harry Bauer has been kicked out of the military, the only job he's ever loved. Now he’s back in New York, and unemployed—until Russian Mafia boss Peter Rusanov offers him a job wiping out the Albanian Mafia. It’s a job he figures could make him rich, until Colonel Jane Harris shows up, takes him for a ride to Pleasantville, and tells him about Cobra. Then all hell breaks loose.

After a covert mission became personal, the only way elite counterterrorism operative, Alexander King, could keep his loved ones safe, and the eyes of Washington's enemies blind to his existence, was to disappear. A year after his family buried a body they thought was his, King saves a young woman from a car bomb in London, and that's when his work in the shadows becomes complicated. Because she's not who he thinks she is, and the web that King is pulled into is tangled with enemies that reach the highest levels of the United States government.

The world knows him as a handsome, charismatic, and successful young businessman. The CIA knows Xander as the US military's most legendary soldier, turned vigilante assassin, who sharpens his skills in the shadows until he can exact revenge on the monster that murdered his family. They have watched his double life go on long enough, and now the government wants their weapon back. Xander has different plans. After a passionate night with Hollywood sweetheart Natalie Rockwell is violently interrupted by a surprise attack at Xander's home, those plans are set in motion.