You ask, Jason [the prisoner Palemides spoke], which aspect is most distasteful of the assassin's art. Knowing you as the paragon of probity you are, you no doubt anticipate some response involving bloodguilt or ritual pollution, perhaps some physical difficulty of the kill. It is neither. The hardest part is bringing back the head.
You have to, to get paid.
Athens and Sparta fought for dominion over what's now Greece and part of Turkey: Athens with its famous navy and Sparta with its famous army, and both with rosters of more or less reliable allies. Before its final defeat, Athens made a rather remarkable showing. At this distance in time it seems as though Athens defeated itself. In their fear of tyranny, the Athenians had made almost every office elective--including the military offices. What happens when a political faction succeeds in forcing the ouster and trial in absentia of the ambitious supreme commander of your armed forces--in the middle of a war?
Such is the setting for Tides of War: A novel of Alcibiades and the Peloponnesian War, as seen by Palemides (and his defence attorny Jason), a soldier, mercenary, marine, slave, bodyguard, and eventually hired executioner. Alcibiades was, of course, the historical large-than-life commander whose vision and charisma drove the course of the war; and whose god was Necessity. Necessity seems to have always meant taking bold steps to expand the empire... no matter which side he was fighting for.
I found the book a page-turner, though I didn't like it as well as Gates of Fire--probably because the hero is rather a less pleasant character, and partly because the interrupted flashback approach breaks the flow. Alcibiades sometimes comes across as a bit too much larger than life, but that may just be because I've not run across people like him or like Rogers from Northwest Passage, (which this book reminds me of).
I've a rough-and-ready rule for measuring how good a book is: How often do I reread it? Lord of the Rings I've reread many times, for example. I suspect I'll come back to this again someday.