George R.R. Martin fans awaiting his next book might ease their craving for mythic heroism, internecine warfare and depraved royals with Caleb Carr’s absorbing new novel. Set circa A.D. 745, during Europe’s Dark Ages, The Legend of Broken straddles the line between epic fantasy and alternate history.

In a brief introduction, Carr claims to have discovered an ancient document that he has brought to light, complete with copious footnotes. This post-modern folderol makes for a rather contorted opening to what quickly turns out to be an excellent and old-fashioned entertainment that evolves into a clever discourse on the history and development of modern warfare. Best known for such novels as The Alienist and The Angel of Darkness, Carr is also a noted military historian. The Legend of Broken has none of the fin-de-siecle trappings that distinguished his earlier novels, but he has a gift for integrating historical detail with lurid spectacle.

The fictional Kingdom of Broken occupies the part of modern Germany that includes the Harz Mountains and remnants of the vast first-growth forest that once covered much of northern Europe. The people live in a mountaintop city carved from granite. In the shadows of Davon Wood, live the Bane, 4-foot-tall humans (don’t call them halfings or dwarves) who were exiled 200 years earlier by its founder, Oxmontrot. Known as the Mad King, Oxmontrot forsook his roots as an adherent of the Moon Goddess to embrace a hedonistic religion with a beautiful male avatar, Kafra.

Now, centuries after Oxmontrot’s death, the Bane and the people of Broken are drawn into open conflict, while both races are being decimated by mysterious plagues. A trio of plucky Bane and a wise military leader of the Broken named Sixt Arnem must venture into the surrounding countryside and attempt to save their respective peoples.

Carr’s depiction of Eighth century Europe as a gallimaufry of religions, superstitions, science and cultural tradition is marvelous: His Dark Ages contain incandescent flashes of insight into an era that itself is often resigned to a mere footnote. His notes initially seem intrusive — imagine Tolkien footnoting every cry of “A Elbereth Gilthoniel!” — but his commentary soon becomes a compelling counter-narrative, where magic is displaced by science and the Bane archers and Broken cavalry become part of a military continuum that stretches from ancient Greece to the present day. Lest this all sound too all serious, be aware that a legless sorcerer, his one-legged acolyte, talking birds and the legendary white panther of Davon Wood (a holdover from Pleistocene days) play a major part in the final confrontation.

But Carr’s tale grows deeper and darker as it proceeds, and he seamlessly blends epic adventure with serious research and asks questions that men and women grappled with in the Dark Ages — and still do today.

Elizabeth Hand reviewed this book for The Washington Post.