"Matter is as really awful and unknown as spirit," the man explained in a tone that suggested it all should be perfectly plain to a child. "Science itself but dallies on the threshhold, scarcely gaining more than a glimpse of the wonders of the inner place."
"Yes, quite. I see what you mean," I replied, though frankly I didn't.
Within an hour the altar stone was tilting backwards, counterbalanced by Tubby, and there lay revealed — But how shall I describe it? I don't know if you've ridden much through the tunnel-of-horrors featured at the better amusement parks, but the scene before us reminded me strongly of same. Through a nearly square opening in the tiled floor, sprawling on a flight of stone steps, was a ghastly array of human or semi-human bones. Not a pretty sight, you understand, but at least there was a cool breeze with something of freshness in it blowing up the arched passage. I mean to say, it could have been a noxious rush as from a closed vault. We did not pause long, but shiveringly began to cut a swath through the ancestral debris down the steps. It was then that Jeeves noticed something odd.
"You will observe, sir, that the hewn walls of the passage, according to the direction of the strokes, must have been chiselled from beneath."
"From beneath you say, Jeeves?"
"But in that case—"
"For the sake of your sanity, sir, I would advise you not to ruminate on the implications."
It's a fun little pastiche, with all the requisite references to Aunt Agatha, Bertie's childhood prize for scripture knowledge, and of course the stars being God's daisy-chain; Bertie bumbles along only vaguely aware of what's going on around him as various antiquarians expound in Lovecraftian circumlocution, and then of course faints or is knocked senseless just as Jeeves steps forward to deal with whatever cosmic horror they happen to be confronting. I particularly liked the way Cannon made use of Bertie Wooster's missing "weekend engagement to Pauline Stoker".
Unfortunately, it's also very short. Very, very short. It is in point of fact 86 pages long, with 21 of those pages being taken up by a rather pointless rumination comparing and contrasting the lives, work, and general outlook of P.G. Wodehouse, H.P. Lovecraft, and Sir Arthur Conan Doyle. As a fan-made vanity-press publication, sold for $7.95 in 1994, it was a good deal. As a rare, OOP book acquired for $50+ from Dreamhaven books, it was something of a letdown. Just when it's starting to really get rolling, that's all there is.
(The end essay recommending Joe Keenan as the best contemporary heir to Wodehouse didn't help, but I'm willing to concede that's a matter of opinion.)
So all in all, if you happen to find a copy of Scream for Jeeves mouldering on the shelves of a used bookstore and can get it cheap, or can manage to abscond with a friend's copy for the two hours total it will take to read it, I highly recommend it. But be ready for it to go "fut" just as you're really getting interested.
I'm half tempted to write a sequel based on At the Mountains of Madness, tho...