When a French archaeologist arrives in 1830s Istanbul determined to track down a lost Byzantine treasure, the local Greek communities are uncertain how to react; the man seems dangerously well informed. Yashim Togalu, who so brilliantly solved the mysterious murders in The Janissary Tree, is once again enlisted to investigate. But when the archaeologist's mutilated body is discovered outside the French embassy, it turns out there is only one suspect: Yashim himself.