The Wizard Knight is a series of epistolary novels written by fantasy and science fiction author Gene Wolfe.

It chronicles the journey of Able of the High Heart, an American boy transported to a magical world and supernaturally aged to adulthood.

The two volumes in the series are: The setting of the novel features elements from Norse, as well as Christian theology and a smattering of European sources, such as Arthurian myth, and involves a seven-tiered world that is separate, but not completely detached, from ours.

The world above it, Skai, is the domain of the Overcyns, who are roughly analogous to the Æsir of Norse mythology, and to whom the inhabitants of Mythgarthr properly owe fealty.

Able's character is that of a young American boy from the modern era who is captured by Aelf, who bring him to the land of Aelfrice and eventually release him in Mythgarthr.

After a brawl in which Sir Able is nearly killed, he accepts a knightly quest to hold a pass against all comers till the snow closes it.

On his way to the pass he joins company with a talking cat named Mani and then a diplomatic expedition led by Baron Beel who is taking presents to Gilling, king of the Angrborn, the giants of Mythgarthr, in an attempt to bring an end to the constant warfare between the giants and the human kingdom of Celidon.

He is brought by Alvit, a Valkyrie to the Valfather's castle in Skai, the realm above Mythgarthr (a clear parallel to the Norse idea of Valhalla).

The second book, The Wizard, begins with Toug helping Baron Beel's diplomatic expedition in the capital city of the giants.

Baron Beel's daughter, Idnn, marries the king of the giants shortly before he dies, and then claims rule over the giantesses of Jotunland.

With Sir Able's help, Baron Beel's expedition retreats back to the realm of men, defeating a host of giants along the way.