The Diary of Otto Kandinsky is a companion novel to the Heavenfield series, and takes the form of a series of journal entries from a young soldier, recruited to the Exile cause. Set in the times before the first Heavenfield novel, when the Exiles built their Fortress and began to increase their fighting strength, it follows Otto through his training to become a member of the notorious Wraith squads - messianic warriors tasked with assassinating key figures around the globe in a desperate attempt to put a stop to all Heavenfield research. Otto becomes an unwilling fighter, his loyalty to the 'Holy Land' keeping him in the struggle against ever-stronger forces that assail them. Picked to lead a squad of the Exiles' latest armoured fighting vehicles, at only nineteen Otto is already a seasoned veteran of many conflicts, and finds himself in some of the bitterest fighting at the onset of the Heavenfield wars. As events run up to those detailed in the first Heavenfield novel, Otto must help salvage the remains of the Exiles' cause, and ultimately join forces with his previous enemies, as they unite against an overwhelming force that threatens to bring the world to the brink of destruction.