does "RMP" mean "Royal Marines"? In the darkness of his office, his thoughts veered suddenly and unhelpfully back in time, to the most personal death of all; the one that Lucy assumed, quite wrongly, haunted Strike’s every investigation, colored every case; the killing that had fractured his and Lucy’s lives into two epochs, so that everything in their memory was cleaved clearly into that which had happened before their mother died, and that which had happened afterwards. Lucy thought he had run away to join the RMP because of Leda’s death; that he had been driven to it by his unsatisfied belief in his stepfather’s guilt; that every corpse he saw in the course of his professional life must recall their mother to his mind; that every killer he met must seem to be an echo of their stepfather; that he was driven to investigate other deaths in an eternal act of personal exculpation.