Where, oh where, to begin with this one? There's so much packed into Poul Anderson's 1961 novel Three Hearts and Three Lions that a thorough review would go deep into spoiler territory. And its only about 200 pages.
Okay. First, the plot. Holger Carlsen is a Danish-born engineer and former college athlete living in Pre-WWII America. When the war breaks out, he returns to Denmark and hooks up with the Danish Resistance and during a desperate mission to extract a scientist to Sweden, a bullet grazes his head and he passes out.
Waking up, he discovers himself naked in a forest with a horse waiting nearby with a set of clothes, weapons and armor. As you do.
The horse's name is Papillon (French for “butterfly”) and with the stallion, he rides to a cottage and gets advice from an old witch who sets him up with a dwarf guide named Hugi. Holger wants to know two things: How to get home, and who is this famous knight with a shield with three hearts and three lions that he's supposed to be.
He encounters a young swanmay named Alianora. She's a human girl who was gifted a cloak that allows her to change into a swan. She, like most of the other people in this world, speak in a stylized dialect meant to sound archaic that takes some getting used to on the page.
After barely evading entrapment by the Elven King Alfric of Faerie, Holger has a run-in with Morgan Le Fay, who knows him from his forgotten past, and he and Alianora begin to fall in love, though his desire to return to the Earth that he knows prevents him from acting on his feelings for her.
Holger finds himself swept up in a grander cosmic conflict as a champion of Law against the fickle and deadly Faerie armies of Chaos. Werewolves! Magic Swords! Dragons! Riddling Giants! Trolls! Heroic Saracens! Comic Relief Wizards! Throwing an Elf into another Elf! True Love!
Much has already been said about how much this story in particular has had an influence on the development of Dungeons & Dragons. Law and Chaos are foundational for the alignment system. The rapidly regenerating troll at the end that can only be permanently harmed by fire is translated directly into the Monster Manual instead of the traditional Scandinavian rock troll (though the fight with this troll is far more hardcore than anything I've seen presented in other stories). Swanmays, Nixies, Unicorns, all have their folkloric predecessors, but again, they are translated almost directly into D&D creatures from this book.
The Paladin, though, is one of the most famous/infamous D&D classes, and it comes from this book. Everything the Paladin class does in Advanced Dungeons & Dragons is done in this story. Detect Evil? Yep. Character is bonded to a special mount? Yes. Immune to fear? Yes (though in Holger's case, much of it comes from being a man of action and an engineer trying to figure out practical reasons for why magic is happening around him) Laying hands on the sick to heal them? Symbolically, yes. Losing certain protections and bonuses when he begins to have impure thoughts? Yes.
Its all there. This book is the bridge between Charlemagne's heroic knightly warriors and Gygax's knights in heavenly armor. I knew that going in, and it still blew my mind to see it in action. (Incidentally, I recommend reading The Song of Roland, where Charlemagne's paladin Roland gets his famous last stand. Badass action and Charlemagne pulling on his beard in grief abounds)
The key to Holger's powers is faith. True faith. Cold Iron, the Cross, and sincere invocations of Jesus Christ all cause physical harm to the forces of Faerie, who are frequently described as having no souls. The tangible power of faith on this strange world shifts Holger from being a modern agnostic to someone who converts to Catholicism by the end (Anderson himself was apparently agnostic with a favorable attitude toward Christianity)
The book features a lot of lighthearted comedy. Holger's no idiot, but he can be a blockhead, especially around pretty ladies. The book takes frequent pauses to think up scientific reasonings for things, like how a dragon would work, or the principles behind a dagger that can be lit on fire. These excursions never get too long, but occasionally they get close.
Then, when the book gets serious, it fully commits. When Holger is presented with the challenge of identifying a werewolf that is terrorizing a town, he gets put into an emotionally difficult situation. Without spoiling it, he has to choose between two grim options, and in true Paladin form, chooses a third.
This book is nothing like the deconstructionist cynicism clogging modern bookshelves. Over and over and over, Holger Carlsen proves himself to be a true-blue White Hat style hero without ever becoming boring. Human and flawed, Holger's a dope with the ladies and a hearty drinker, but at every turn he tries to do good, and in return, becomes a better person and betters the world around him. This is the kind of heroism I've been starved for, and here it is, fully realized by a Grandmaster of Science Fiction.
I can't recommend this book enough. Read it, if for no other reason than to understand how Paladin characters are meant to be played.
Gorgeous Darrell K. Sweet cover for the Baen edition
“And some say he waits in timeless Avalon until France the fair is in danger, and some say he sleeps beneath Kronborg Castle and wakens in the hour of Denmark's need, but none remember that he is and has always been a man, with the humble needs and loves of a man; to all, he is merely the Defender.
“He rode out on the wold, and it was as if dawn rode with him.”