Tyler and Shannon are both foster children with a murky grasp of their past... and a startling alternate identity of hardened killers. When their burner phones ring and someone says "Olympus is rising" to them, they respond with "Pandora's box is open" and go off on their next mission. In between, they have a growing realization about what is going on. Tyler in particular starts to realize what he is going, and tries to stop it. When he attempts to leave the organization, Shannon is sent after him to neutralize him.
In alternate chapters, we also see Hades, who is another born and bred killer. When there is not target available, he tries to sublimate his urge to destroy by eating and working out a lot. When he meets Elizabeth, the daughter of a politician, he starts to have strong feelings for her. She is tired of going to her fancy private school and always having to behave, and is drawn to Hades, with his tattoos, motorcycle, and leather jacket. In turn, he decides that she should become one of the teen assassins, and starts to indoctrinate her into the program.
We are given some information about Project Pandora, and learn that there are children who were conceived and born in labs, only to be handed over to foster families after their brains are wired to be assassins. Dmitri is one of the forces behind the project, but it is all rather shady and ill defined.
Tyler and Shannon want to break free; Hades wants to delve deeper into the program and bring Elizabeth with him. What exactly is Project Pandora, and how many people will have to die before its evil ways are brought to light?
I liked the four main characters, and found their evolution to be interesting. Elizabeth was particularly intriguing, because she had such a nice life with her rich, overprotective parents, but felt compelled to get free of the restraints of this life, much to her own peril. Shannon and Tyler are equals and friends, and work together to try to figure out what their role in the project is. Hades was a classic bad boy; he isn't supposed to be charming, but is anyway.
I would have liked to know a lot more details about the Project and what its purpose is, but I imagine those details are going to be covered in the next book. For now, readers who like edge-of-their-seat novels with plenty of gore will find Project Pandora to be quite a page turner.