In Professor Layton and the Eternal Diva, Professor Layton leads Pierre Starbuck and Celia Raidley in the wrong direction from what the puzzle directs, and the two fall in a pitfall. Layton assures them he will return after everything is over to rescue them. However, the castle they are in transforms into a giant robot. Pierre and Celia were still in that castle, and most likely got squished while it transformed. Even worse, if they weren't dead inside the giant robot, then Layton destroyed the robot and killed them. Professor Layton is a Murderer.
Stick around for the usual credits roll pics. They're fine.
And besides, it's never clearly explained why he went in the wrong direction; Layton was probably just investigating, and didn't think that those two would follow him.
In Professor Layton and the Last Specter, shortly after Layton befriends Luke, Clark suddenly raves about the Professor's knowledge of wine and asks him to select one for dinner. Layton privately considers this odd — his old friend, of all people, should know that he's clueless about wine — but has a look regardless, a wine-themed puzzle ensues, and that seems to be that. Later on, it's revealed that Descole was keeping Clark's kidnapped wife prisoner beneath the wine cellar. It's then that you realize: Clark was trying to clue Layton into the fact that something was amiss in the cellar, and not only Layton but both his companions failed to actually do anything about it. So 1. Clark's desperate last chance to save his wife was ruined because Layton got preoccupied in arranging bottles, and 2. Luke was maybe meters away from his beloved Missing Mom and had no clue about it. Just try to imagine how Clark must have felt throughout that supper!
In Professor Layton and the Unwound Future, you learn that Future London is a fake, and the Clock Shop is actually an elevator that takes its riders underneath the actual London to the fake Future one. While it's implied that the actors who pretended to be the inhabitants of future London didn't know what Clive was planning, like Cogg and Spring, the game mentions that at least one of the scientists is married. While it's bad enough for the scientist (whose name escapes me), it's indicated that Viv is the daughter of one of the scientists and one of the actual "residents" of Future London. She must have been born after Future London was established, if she truly was the daughter of the scientist. Imagine what it must have been like for her when Future London was evacuated. Imagine, at a young age, learning that your entire LIFE is a lie, a facsimile designed to disguise a horrible weapon of mass destruction, and more personally, your mother knew the truth, but didn't tell you. That could leave someone SERIOUSLY traumatized.
The last time a child was seriously traumatized by a bizarre and tragic incident, he ended up trying to destroy London and someone present at the original incident in his youth had to stop him. This time? Call in Professor Triton!
In Professor Layton and the Miracle Mask, it is revealed that Angela was actually Descole in disguise for a few days. Seems like typical Descole, until you realise... Angela is a married woman. And Descole was together with Henry for at least one in-game night. Put two and two together. Sure, it was a marriage of convenience, but as Descole wasn't aware of the true relationship between the two...
If he had instigated anything though, wouldn't Henry have known it wasn't the real Angela? Unless Henry took the initiative on this one, I don't think anything would have occurred, and I think he was probably too busy freaking out over the Masked Gentleman to think of it.
Descole wouldn't be stupid enough to try initiating anything. The jig would have been up the moment Henry noticed a few key anatomical differences between the two.
It doesn't change the fact that Descole was unaware of the "fake marriage" (unless he spied on the Ledores before masquerading as Angela, which is something I don't want to think about), yet he was perfectly willing to disguise himself as Angela anyway.
The losses of Randall in Akbadain and later Claire in the time machine experiment both explain Layton's reluctance to allow Flora near anything remotely dangerous - and his ungentlemanly behaviours in regard to this (such as leaving her at home, sneaking out without her, etc.) Poor Hershel. He's already lost one of his close friends and the love of his life - the idea of also losing his daughter probably terrifies him half to death.
He also tried to do the same thing to Chelmey, Barton, and even Luke shortly after in Unwound Future, because he had experienced first-hand the dark conspiracy behind the time travel experiment when he was beaten by hired men and robbed of all his research on the matter several years ago. So he's generally protective of everyone he cares about, but Flora is the one to whom he exhibits this behavior most consistently.
Toward the end of Miracle Mask and again in The Stinger, we learn that Broneph has taken control of the featured ruins of Last Specter and Eternal Diva. Sure, the kingdom of Ambrosia was abandoned, but what does that mean for the citizens of Misthallery, including young Arianna and Tony?
Considering the picture you get if you solve all the puzzles in Last Specter, which is proven to take place after Curious Village by the presence of Flora, they're fine.
Clark and Brenda Triton show up in The Azran Legacy as they're currently working on an archaeological research in London. No mention is made of anything happening to Misthallery, therefore we can assume Targent simply sent some researchers to scout the Golden Garden (like they did with the wall of Norwell in the past) rather than seizing control of it with their military.
In Miracle Mask, Descole-as-Angela says he knows the Professor only played along with him because he needed help on the final puzzle to raise the ruins. Why? Emmy and Luke were both there; Layton just needed another body, not anyone specific.
Layton didn't know what the final puzzle was until he came across it. Having his highly intelligent archaeologist archnemesis around would certainly be useful in case he needed to figure something out. And he also kept him under control this way. Not to mention, we as players are explained the rules of the final puzzle as soon as it begins, but keep in mind Layton had to figure them out first in-story. It's likely Descole helped with that while Luke and Emmy couldn't have.
The spinning stone rings in the title screen of Miracle Mask? They're a simplified representation of the Infinite Vault of Akbadain, which, unlike the previous two archeological wonders, has nothing to do with the current story's plot... but, along with the other two, has everything to do with the final game.
Layton and Henry are more alike than they ever realized. After Randall's supposed death, Henry continued being his butler, not only looking after was was rightly Randall's in case he ever returned, but also doing minor jobs like dusting. He was trapped in the role, and when Randall returned, he probably never did another bit of housework again. While Henry was trapped in the role of a butler, Layton was trapped in the role of a proper British gentleman as a result of the loss of Claire, whose joke about him becoming a gentlemanly university professor resulted in a years-long obsession. Both Henry and Layton became psychologically trapped behind stereotypically British facades as a result of loss, and only closure could free them.
One of the collection items is the Enigma Coin. Upon gaining the coin Layton and Luke claim how it looks like a fake hint coin. On closer inspection of the coin it does look like a hint coin, complete with top hat, forest-y colors and the letter "R". The comment in the collection chest says it looks like a hint coin "but what does the R stand for?" This is where the brilliance comes in. Without a second thought the hat on the coin belongs to Layton, but the colors suggest otherwise. Who else wears a top hat? The Masked Gentleman. Then what does the "R" stand for? Randall.
That's definitely not enough evidence, though. It could stand for Reinel, or Reinhold, or Rudolph, or any other name that starts with "R".
True, but are there any other names that start with "R" within the miracle mask game? Certainly no one called Rudolph. I see where you're coming from but you're thinking way too outside of the box.
Here's why it's called the Enigma Coin and has the letter R. In Azran Legacy, it is revealed that Layton and Descole are related, and their father is Bronev Reinel. The Enigma Coin is stating that the name Layton is an enigma of his past self, Leppard Reinel, which is his birth name, and that the last name Layton is an enigma. Foreshadowing at its best.
I saw a lot of headscratchers about the hallucinogenic in Folsense, and the fact that it apparently made a shared hallucination. But when you think about it, we don't know that. From arriving in Folsense, everything is from the perspective of Professor Layton himself, and while he interacts with other characters, that proves nothing due to the hallucination element. The gas can cause people to hallucinate death, and therefore fall into a coma. Making Layton warp any conversations in his head so as to fit his perspective is easy. And Luke or anyone else never got frantic about Layton acting differently because from their perspective he was just giving the reactions they were expecting.
At the end of Azran Legacy, we learn that the Azran fell as a result of a Robot War, because they developed sapient AI golems and yet refused to treat them as anything but tools. This provides a thematic link with Curious Village, the next game chronologically: Layton proves that modern humans have a better understanding of such things by treating the robotic villagers as people worthy of respect.