In the fourth episode of this epic saga inspired by the Mamluk slave-dynasty of Egypt, Shajar, the Sultan's chief wife (Sarah Beck Mather), plots her son Madu's (Danny Ashok) succession to the throne. While Gregor, Master of the Palace Guard, is determined to discover what it is she has taken from the aged Hafiz and is having repaired in the workshop of a pair of artisans in the city. Marching with the army out to the provinces, Madu's slave find solace with an unlikely companion.Tumanbay, the beating heart of a vast empire, is threatened by a rebellion in a far-off province and a mysterious force devouring the city from within. Gregor (Rufus Wright), Master of the Palace Guard, is charged by Sultan Al-Ghuri (Raad Rawi) with the task of rooting out this insurgence and crushing it.Music - Sacha PuttnamSound Design - Steve Bond, Jon OuinEditors - Ania Przygoda, James MorganProducers - Emma Hearn, Nadir Khan, John DrydenWritten by Mike WalkerDirected by John DrydenA Goldhawk production for BBC Radio 4.