The Eyes of the Overworld but was actually granted status as an authorized sequel by Jack Vance himself. Though eventually displaced and de-canonized by the appearance of Cugel's Saga, A Quest for Simbilis was nevertheless well received, establishing Shea as a master of description and mood. Despite this early success, aside from a few short stories, Shea didn't produce another novel for nearly a decade, until Nifft the Lean appeared in 1982.
Nifft the Lean is not set in the Dying Earth, but there's no denying that there are more than a few connections between it and Vance's famous setting. For one, it's setting seems to be a world that may or may not be a future version of the Earth, eons after the fall of our current civilization, after magic, gods, and demons -- or at least seemingly magical, god-like, and demon-like things -- have returned. For another, the book's eponymous protagonist is a ne'er-do-well on the make. Also like The Dying Earth, Nifft the Lean isn't really a novel so much as a collection of four short stories. Granted, each of these short stories features Nifft in another adventure, but each can be read independently of the others and there is no overarching story connecting them.
I suppose one could make the argument that the book is really a picaresque novel, especially since Shea presents these short stories as a series of reminiscences by a friend of Nifft, a scholar by the name of Shag Margold. Margold speaks in a pedantic, persnickety fashion as befits his role and reports to the reader that Nifft is dead and thus the stories that follow are his recollections of his friend's adventures, as told to him by Nifft himself and others, which is why they are told in the first person. This admission allows Shea to spin what might very well be tall tales rather than the unalloyed truth, which, given the nature of a couple of the book's integral stories, would explain a lot. Furthermore, Margold stresses that he was not present during any of these adventures and has had to rely solely on others for accounts of what occurred.
The first story in the collection concerns Nifft's attempt to bring a living man into the underworld at the behest of the spirit of the lover whom the man has betrayed. In return, Nifft has been promised the key to a wizard's mansion, where untold wealth is said to lie. To win his reward is no easy task. The second story involves a journey into a dangerous swamp in order to harvest black swamp pearls that grow on the bodies of deadly polyps native to the morass. Naturally, Nifft has a plan designed to make acquiring the pearls easier for him. The third story sees Nifft and his companion being falsely arrested and, in order to escape the penalties imposed on them for their "crimes," must rescue son of a rich man, who has been abducted by an inhabitant of the Demon Sea. This story is by far the longest in the book and it shows, dragging on to the point of tedium in places. The fourth and final story involves Nifft in an attempt to save a city from the collapse of a nearby mountain whose foundations have been weakened due to over-mining.
Nifft the Lean is an uneven book, but it's still a fairly engaging one. As I noted above, Michael Shea possesses a superb command of description and mood. His characters and, to a lesser extent, his plots are a bit shallow, or at least more straightforward than one might expect of an author whose debut novel was a sequel to The Eyes of the Overworld. Shea is no Vance but I think he can favorably be compared to Clark Ashton Smith, whose best tales achieve their brilliance more by the evocation of a mood than by tight plotting or deep characterization. That's not to say that Nifft the Lean is purely an exercise in mood creation, because all of its integral stories are fairly satisfying pulp tales, despite their flaws. Moreover, Shea has a very vivid imagination: his inhuman monsters and otherworlds are memorably weird, which makes this book well worth a read by any fan of fantasy literature. Shea may be no Vance but he nevertheless offers more of interest than many more well known fantasy authors, particularly if your tastes tend toward the dark and outré.