It may be a bit misleading, as it shows several items from the story all at once - that is, it is NOT a scene you will find within. At the bottom you can see the main characters: the triplets Mike, Mark, and Matt Weaver, and their friend Tom Felsen; and on the right Joe Outis at the wheel of his grandfather's boat Remmirath with Mike Tronder.
Above is the artist's attempt to show the Wreck against the backdrop of the vista looking west, into the little bay of Quayment from out in the Atlantic - to the left is the lighthouse on the Point; to the right is the "young cathedral" of St. Ambrose's, at the top of the north hill (yes, it also has a warning lamp for sailors), and the strange dome on the top of Weaver's Bookstore, and the huge complex called "Benny's" (the real name of which is "Levin Shipping") with its lighted menorah. In the left midground is the doomed Greek cargo ship Phosploion, now burning and sinking rapidly, with the Remmirath in flight.
At the top... ah, well. Where the beams from the Great Lights of Quayment cross is that archival storage bag containing a fragment of the letters of St. Bernard - a document printed in 1494... and Something Else... but I shall not here reveal what it is. And if you are wondering about the blue and violet arcs, faintly visible near the top... well then I suggest you get the book. You see, I am bound by the Great Law of the Story, so wonderfully phrased by G. K. Chesterton:
Nothing would induce me to tell the reader anything about the solution of the riddle. The man who tells the truth about a detective story is simply a wicked man, as wicked as the man who deliberately breaks a child's soap-bubble - and he is more wicked than Nero. To give away a secret when it should be kept is the worst of human crimes; and Dante was never more right than when he made the lowest circle in Hell the Circle of the Traitors. It is to destroy one human pleasure so that it can never be recovered... [GKC ILN Nov 7 1908 CW28:210]