Robert de la Borde comes to England in the 1980's from the Caribbean after hearing that his brother, Jean Marc, has died. In Bristol, his brother's journals prompt Robert to visit Ashton Park Monastery, which Jean Marc entered in the 1960's as Brother Aelred.There, with the help of his brother's monastic friend Benedict, Robert pieces together Jean Marc's life; his exuberance, his mental suffering, and his struggle to balance his sexual impulses with his love of God, as set out in the work of Aelred of Rievaulx, Spiritual Friendship, against the austerity of Catholic sexual morality. In his understanding, Robert also learns what connects Jean Marc to Jordan, the African slave-boy captive at Ashton Park during the eighteenth century.As Robert is forced to question his inherited prejudices and to confront another ghost of Jean Marc's childhood – the events concerning Ted Salter – what unfolds is a story about the triumph of compassion over brutality. Moving from present to past, from cruelty to sympathy, Aelred's Sin is a powerful new novel of erotic love, spiritual awakening and above all, reconciliation.