Killer in the Cloud tells the story of Michael Wesley, a Garda working in the fictional town of Kilcrew, Co. Roscommon. Following the death of his boss, Wesley begins to examine the unsolved murder cases of the town, in a bid to save his station from closure. When details of his investigation are published in a local newspaper, Wesley receives a strange package and realises, with the help of an old friend, that there might be more to the cases than meets the eye.