Afghanistan, 2012. Mackay Connolly has been medically discharged from the British army following an IED explosion killing three members of his team. He barely survives. To keep Mackay alive, a cutting-edge synthetic bone structure called Phragazom is implanted.

Back in the UK, PTSD engulfs him, leading to a deep depression. However, a budding friendship with Renee Cross, a wheelchair-bound military boxing instructor with her own traumatic past brings a glimmer of hope.

When tragedy strikes again and Mackay's brother and most of his family are killed at an Australian winery, he is driven to uncover the truth and find his surviving nephew. Together, Mackay and Renee embark on a quest, travelling from one corner of the world to the other to bring those responsible to justice. Mackay, however, has no idea how powerful his synthetic upgrade really is…