As a theological argument, Descent into Hell may make for good fiction, but as a novel, it leaves much to be desired. While many proclaim this the finest of Williams's works, that proclamation probably needs some scrutiny and qualification to make any sense. Perhaps the acclaim is for the interesting concept and final delivery of the book; if so, the acclaim may be justified, as the novel presents one of the more interesting climaxes in the Williams oeuvre, and the most explicit and consistent spelling out of Williams's pet doctrine of substituted love.
However well or poorly it may function as speculative or practical theology, it does not function well as a novel, not even as a novel of ideas. There are several reasons for this. The prose is tortured to the extreme, taking a long time (even for Williams) to get to the point.
The dead man had stood in what was now Wentworth's bedroom, and listened in fear lest he should hear the footsteps of his kind. That past existed still in its own place, since all the past is in the web of life nothing else than a part, of which we are not sensationally conscious. It was drawing closer now to the present; it approached the senses of the present. But between them still there went---patter,patter--the hurrying footsteps which Margaret Anstruther had heard in the first circle of the Hill. The dead man had hardly heard them; his passion had carried him through that circle into death. But on the hither side were the footsteps, and the echo and memory of the footsteps, of this world. It was these for which Wentworth listened. . .
And on, and on, and on, and on. "But between them still there went. . ." Between whom? Between the past and the present, between Wentworth and the dead man, between the people of the Hill. The writing is murky, unclear, imprecise, unfinished. There are few pages in the book that do not display at least one hefty lump of prose to match the above. There is about the writing nothing clear and precise, but a seemingly endless grinding of the same grain. Had there been somewhat less, the novel would have occupied perhaps two-thirds of its present length and come to a much stronger and more powerful conclusion for being more direct concerning what it was about. Williams plays too coy with his theme for too long.
In addition, there are few real characters in the book. Mrs. Anstruther and the Poet Stanhope speak in cryptic, labyrinthine sentences that suggest more the Oracles at Delphi than any reasonable character. Wentworth, driven by his own selfishness and ego becomes a mockery of himself (although this is the end of utter selfishness) and Pauline isn't quite firmly enough drawn to bear the weight laid upon her shoulders by the plot line.
The story about which these theological speculations are clustered, the presentation of a play by a group of performers at the Hill, is so trivial as to be at points painful. Doppelgangers, Lamias, ghosts or revenants, and personified elementals all loom large, or rather small as Williams isn't the least interested in any of these, and thus cannot cause the reader to evince interest. Williams is interested in his idea which, while fascinating, hardly makes for compelling reading as a piece of fiction.
In truth, nearly every other book of Williams is superior as fiction. No other approaches it (except perhaps All Hallows Eve) in the courage and strength of its initial ideation, nor in the pervasiveness of the coherent center of the book. Nevertheless, ideas rarely make for compelling fiction. And in this case, the idea, glorious in itself needs a better vehicle than a novel for it to achieve effect. And as the idea cannot be in the ascendant here, neither can the novel based entirely upon the effect of the idea succeed.
If one is inclined to read Williams, it may be better to start with nearly any other work and to find one's way slowly back to this. An appreciation of Williams's prose effects and system of writing may sustain one through the reading of this book, but perhaps only barely.