The Secret Agent of Sarajevo is a coming of age story set in the uncertain weeks leading up to WWI. We experience the unfolding of explosive events seen through the eyes of our hero, Stanley – born Stanislav – a disaffected and naïve young Bosnian Englishman. He is recruited by the British Secret Service Bureau to visit his family in Sarajevo and spy on fanatical Black Hand anarchists there. But things go wrong when Harrington, the master spy helping him, is injured and Stanley has to get to Sarajevo alone, chased by enemy agents. Stanley is an innocent abroad, and when crossing Europe, he falls madly for the hare-brained daughter of an Austrian arms manufacturer. Suspicious of Stanley’s Bosnian heritage, he has him arrested and imprisoned. Rescued by Harrington, Stanley reaches Sarajevo to be united with his motherly Aunt Emina and firebrand cousin Dario, a member of a student revolutionary group, Young Bosnia. He also meets his fiancée, Ramona, whom he falls in love with. The reverse happens when he visits an army uncle in neighbouring Serbia, suspected of being a Black Hand member, when his daughter, with the connivance of her mother, makes it plain she desires to be his wife, something Stanley has no wish for.
While following his uncle riding to a secret Black Hand meeting, he is captured and only escapes with his life after agreeing to join the ruthless Black Hand himself. He is reluctantly thrown in with three young Bosnian assassins training to assassinate Archduke Ferdinand, heir to the dominant Austro-Hungarian Empire and soon to visit Sarajevo. They cross back into Bosnia via a smugglers’ trail with their illegal weapons. In Sarajevo, while waiting for final instructions on the assassination, Stanley is impressed by the sincere dedication of the three anarchists, becoming confused about what he should do, expose the plot or help it to succeed. During this time, he admits his deep love for Ramona, who, although flattered, understandably rejects him. She then asks him to stop Dario getting involved with the assassination. Stanley has to make the most serious decision of his life: does he give up Ramona and save Dario’s life, who will then marry her? Or let him be killed in an arranged suicide pact after the assassination and hopefully have Ramona for himself – and thereby unwittingly start a war?