Jessica Lauren Ball

"When Mycroft Holmes is murdered in London, it is up to retired shadow executive Smith to track down his killer - and stumble on the greatest conspiracy of his life. Strange forces are stirring into life around the globe, and in the shadow game of spies nothing is certain. Fresh from liberating a strange alien object in Abyssinia - which might just be the mythical Ark of the Covenant - young Lucy Westerna, Holmes' protégé, must follow her own path...