The Nijinsky Mark

Harry Hansen and Alyce James were attending a performance of the Maryinsky Ballet at the Barbican Centre when before their eyes Ivan Kalmakov the principle male dancer collapses to the stage at the end of his showcase piece. Kalmakov's death is ruled the result of natural causes by The Yard but Harry thinks otherwise. As Harry and Alyce talk to Ivan's colleagues they began to wondered if there were anyone who did not have a reason to kill him?