WMG / The Fifth Elephant

On the Elephant plummeting to Disc:

• The Circle Sea is indeed circular. Very circular, in fact. A Wild Mass Guessing concept occurs to me here. On Earth, the Caribbean Sea also has a sort of irregular circularity to it. Enough geological exploration has occurred here for science to be reasonably sure a massive meteorite, or perhaps a comet or small asteroid, impacted here, off the coast of what is now Mexico, in one of those events Rincewind gloomily recorded for posterity in The Science of Discworld. You know, the sort of thing that in a well-ordered Universe only ever happens in Outer Space, which as we know begins a few planets away at a nice safe distance where our telescopes can watch the fireworks. This Snowball Event happened a billion or so years ago, apparently, but its mark can still be seen today - apparently the Caribbean can be viewed as one huge impact crater that eventually filled up with water. Now on the Discworld there is the legend of the Fifth Elephant that fell off and owing to the strange gravitational field of Great A'Tuin, fell to earth again. What if the greater mass of the falling elephant created an impact crater which then filled with water? After all, Uberwald is not far Hubwards and the Dwarfs are still mining the bounty... but a World Elephant must logically impact over an area at least a fifth of the size of the entire Disc... what if only the smaller part of it is available for mining under Uberwald? The rest of it had to go somewhere...
  • Uberwald is certainly a place where the veins run near the surface, and give rise to seeps. Perhaps there is a similar seep on the floor of the Circle Sea, and it is gases from the slow anaerobic decomposition of the exuding fat that provide for the periodic flotation of Leshp.
  • Though the Carribian Sea is indeed more or less circular, and there has indeed been an impact from a massive meteorite off of the coast of Mexico, the crater the meteorite left behind is only a fraction of the Carribiean Sea. According to Wikipedia, the crater is 180 kilometers in diameter, which makes it the third largest known on earth. On top of that, an impact that happened a billion years ago (the event you were referring to happened only 66 million years ago) would not have any visible features or even hidden features anymore due to plate tectonics. A few hundred million years is the most you're gonna find in most places in the world.
• Why did the Fifth Elephant fall in the first place? Well, in The Light Fantastic, the story of the Disc approaching a strange red star eventually resolves itself as Great A'Tuin keeping an Eye on eight Space-Turtle eggs, which eventually hatch as eight tiny baby Discworlds, baby turtles carrying elephant-cubs on their backs supporting proto-Discs wreathed in volcanic fire, which swim away from the nurturing light of the Star into Deep Space. Why did Great A'Tuin care enough to want to see if the eggs were OK? Does this offer a clue as to the gender of the Space Turtle, a theme imaginative astro-zoologists have worried about since time immemorial? Could it be that She nipped back to check on the nursery and see the kids were OK? Which implies that there are other Discs out there, and at some point in the past, Great A'Tuin actually mated with a male astrochelonian (the event imaginative thinkers dreaded). This implies that the worst-case scenario has actually happened and the Disc survived. But what if the physical exertion of astro-chelonian sex caused something to give - ie, a hapless elephant was dislodged from the Disc and impact on top of it a while later...
  • Given that the baby turtles came equipped with only four baby elephants under their mini-Discs, it seems more likely that four is the standard number for a Discworld and the whole "Fifth Elephant" idea is a fable. Unless, of course, it was one of the elephants of A'Tuin's mate that slipped off and landed on the wrong Disc...
• Is it all a disguised Shout-Out to Douglas Adams, who famously invoked a whale plummeting to the surface of a planet with calamitous results for planet and whale? After all, Pratchett may have felt a need to go one better...
  • In which case, what is the disc equivalent of the small bowl of petunias? There is a constellation in the Disc sky with an interestingly similar name...Gahoolie, The Vase of Tulips. Is this the second shoe, poised to drop?
    • Oh no, not again.

Gavin & Carrot

So, it's mentioned in another book (Thief of Time perhaps?) that reincarnation happens in no particular chronological order, and that it might even give way to preincarnation. Given Gavin's nobility of spirit, his natural charisma, and the way he wears the wolf pack and the forest similar to how Carrot wears the city, they may literally be the same soul incarnated at different times, which would explain why they are so similar.

The Scone isn't unique in being other than is generally known.

• In Feet of Clay, a loaf of Battle Bread alleged to have been wielded by B'hrian Bloodaxe at the Battle of Koom Valley is used as a murder weapon at the Dwarf Bread Museum. However, Thud! establishes that B'hrian and his equipment were never recovered from the battlefield. So where'd the supposed Battle Bread come from? Some previous Low King probably had it baked up from scratch by the same dwarfs who re-crafted the Scone, then claimed it'd been "miraculously retrieved" from Koom Valley. Which should please Mr. Hopkinson in the afterlife, should he learn that his inconvenient murder didn't damage the real Bloodaxe battle loaf, after all.