As himself, Dimitri wears a white lab coat with a red rose on the left side. He also wears a stylish white hat with a light-gray brim. He also is equipped with a gray scarf and a black shirt under it. He has blue eyes and clearly gray hair that covers up his right eye. He has tired-looking eyes, and a few wrinkles, which probably came from stress. In his younger days he wore a yellow shirt and gray tie as well as a lab coat, of course.
When he is portraying the role of Dr. Alain Stahngun he has his regular attire and red tie instead of a rose. Dr. Stahngun, also, has a gray mustache. It is fake and part of the disguise as Dimitri, himself, doesn't have one. Stahngun's hair is in the same style as Dimitri's but has a different, more brown color to it in the cutscenes.
As Future Layton's get up is very similar to the real Professor's in that it has a top hat and the rest of the clothing is also practically the same. His hat is black with a white brim in contrast to the Professor's with a brown color with a red brim. Future Layton also wears a black trenchcoat-looking attire with a white rose on the right side. With these garmets, he also wears a red scarf. Dimitri, himself, wears a gray one. Future Layton tucks his top hat down, most likely to hide his identity as Dimitri Allen. Under the rest of his clothing, Future Layton wears Dimitri's regular get-up, as shown when he takes off the Future Layton costume.
Dimitri, Bill Hawks, and Claire worked a long time on a time machine. They worked in the Institute of Polydimensional Physics in London. Dimitri noticed how the time machine was not ready for use on a human subject yet. Bill, on the other hand, refused and went ahead with the experiment, and with the machine still on an early stage, used Claire as the human test subject to travel in time with the machine. Claire was their lab assistant. Dimitri obviously refused to go through with this experiment, saying that in just a few weeks they could complete it, but Bill didn't listen to him. When Dimitri tried to stop him, Bill already tried to make the machine work.
This caused an explosion that killed many, many people in the apartment building next door. The police report of the incident said that ten people were killed. Although, something or someone was trying to cover up the incident. Some of these people who died included Clive's parents as well as Claire herself. It is revealed that Dimitri, like both Don Paolo and Professor Layton, had loved Claire. So, then he devised a plan to take down Bill Hawks and his political agenda. During the events of Professor Layton and the Unwound Future, Dimitri forms an alliance with a young man called Clive. This boy had a lot of inheritance money, as well as a reason to take down Bill. He began to caputure all scientists to rebuild the time machine so he could go back 10 years to stop Bill from continuing the experiment. What didn't he know that Clive was using scientists to rebuild the Mobile Fortress to destroy London.
Dimitri posed as one Dr. Alain Stahngun to perform a time machine presentation. He proclaimed to have built a working time machine, although many at the presentation said it was a farce and no such device was possible. In attendance of the presentation were: Inspector Chelmey; Constable Barton; Bill, and his wife Caroline; Professor Layton; Luke Triton; and many scientists and highly respected citizens who lived in London. However, the presentation failed and Dr. Stahngun, Bill, and the other scientists disappeared. Dimitri knew this would happen and kidnapped the others that disappeared into Future London. Dimitri had planned to build a new time machine. To motivate the kidnapped scientists to build it, he told them that they were stranded in the future, a decade from home, with no way but this to return.
According to what Future Luke and Future Layton said about The Family, it started out because of the professor and his work. When Dr. Stahngun vanished he, one day, met up with the professor and they decided to work together for unknown reasons. At first, Layton decided to help Stahngun out by keeping him safe from the law and anyone else who searched for him. Layton then one day became obsessed with the ideas Stahngun had given him. He then betrayed him and became the leader of a new organization that would one day rule all of London. This became known as The Family. Of course, as Layton and Luke solve the mystery later on this was not the actual founding of The Family.
To control the law in Future London, Clive and Dimitri formed The Family. The Family is a group of mobsters who run the city of Future London from the shadows. It controls the police, trade, politics, and the media of Future London. The Family also owns important buildings in the city. The buildings in question are the Towering Pagoda, Gilded Seven Casino, Thames Arms, and the Research Facility.
The Casino was used for profit primarily. This place was a centrally located 24-hour casino inside the northern parts of London. It is found at the northest part of Flatsone Street. The Casino also is where Future Layton's right hand man, Bostro, usually gives out orders and "hangs out".
The Thames Arms was used by Dimitri as a secret safehouse for him to stay hidden and lay low for a while in case something of a crisis were to emerge. Dimitri, posing as the bartender, also used the Thames Arms to unwind a bit and relieve some stress from his profession.
Dimitri posed as the future Professor Layton and was the leader of the Family. His main base of operations inside Future London was the Towering Pagoda. The Towering Pagoda is rumored to be the main base, but it is clearly true that it is indeed a stronghold of sorts.
The Research Facility in the northern side of the Thames Arms was used by Dimitri, other scientists, and guards to build the time machine Dimitri held so dear.
Some time into the game, Layton, Luke, Flora, and Future Luke finally gain access to the Towering Pagoda in Chinatown. It is here that the future Professor Layton rules London with an iron fist. Before they go inside Layton leaves for a while to go investigate the area. He tells his friends not to worry and go ahead. Soon afterwards, Layton returns and they enter the Towering Pagoda. Around the beginning of their journey going up the tower,
Dimitri uses a memory-scanning device to read Layton's mind. The device looks very similar to glasses. Layton was wearing the pair of glasses, unknowing of their true power, to solve a puzzle in order to open up a locked door. Then they solve a few puzzles and get past some guards as they climb the tower further. When Luke, Flora, Future Luke, and Don Paolo (at the time Layton) confront the future Professor Layton in his office at the top of the tower, Layton disbelieves that future Layton is real.
Professor Layton (Don Paolo):"You've put on quite a show, but it's clear to me that you're nothing but a charlatan."
Future Professor Layton (Dimitri):"Oh, is that so?"
Luke Triton:"Professor, what tipped you off?"
Future Professor Layton (Dimitri): "Heh, heh! Yes. What indeed? I'm all ears."
Professor Layton (Don Paolo): "You, sir, are a fraud and I intend to expose you for the imposter you are!"
To prove that the Future Layton is, indeed a fraud, Professor Layton then asks the Future Layton a single question. This question is this: "What color pen do I have in my pocket?" This question turns out to be the very flaw in Future Layton's plan. Luke then solves a puzzle that Layton asks him. The puzzle has Luke finding out which way is up and what happens when the wrong way is picked. Afterward, Future Layton ponders what it has to do with anything. Layton, then, explains why the puzzle he told Luke matters. You see, the Future Layton then guesses the color of the pen. Layton told him that the if he was the real Layton of the Future he would have lived through this moment before and thus would know the answer with ease. It turns out that there was no pen in Layton's pocket. Then Future Layton, due to his wits being bested, reveals that he is actually Dimitri Allen in disguise.
Dimitri then reveals that he has indeed kidnapped Bill Hawks and the other scientists. Dimitri and Layton have a long conversation about his plans and why he's doing them. His actions were because he, like Layton, loved Claire and Bill took Claire from this world. Dimitri challenges Professor Layton to a Puzzle Battle to prove he can't truly be defeated here. After he was bested in the battle, Dimitri captures Layton and co. in a cage he activates. It is at this point Dimitri then tells them of Bill Hawks as he is tied up in a secret chamber in Future Layton's office. Don Paolo, knowing that Layton is almost here, takes off the Professor costume and reveals that he was the one Dimitri has trapped. Then out of nowhere the real Layton reveals himself by the door. Everyone in the room surprised yet confused, Layton then frees them from the cage.
With his cover blown and capturing the fake Layton, Dimitri seems as though all of his plan has failed. Now the real Professor Layton confronts Dimitri. Now that the real Layton has appeared Dimitri tells the heroes of how a large sum of Family goons and guards will be there to protect Dimitri in a matter of minutes. Then Layton says that he can slow them down as he put traps in various locations as he went up the tower. Afterwards he escapes due to Bostro entering the room. Dimitri activates an alarm, alerting Family members in the area to his room at the top of the pagoda. Layton and co. then escape through a secret staircase which allowed Dimitri to sneak out of the pogoda to unwind. As they go down Layton and co split up into two different teams and search the area. Layton, Luke, and Don Paolo are in one team. The other was Future Luke and Flora. Then they all go to the Hotel Duke and then the Thames Arms to discuss their next strategy.
The Future London needed to look more futuristic in Dimitri and Clives's view on the city. So they decided to make quite the large number of various machines all around London. These machines didn't really play much of a role in the story of the game. There was one location built for an actual devastating purpose.
Dimitri built this research facility mainly to build his ultimate Time Machine. The facility was located on the far side of the River Thames and was used by his scientists he had kidnapped. Layton and co. venture off into the facility to find Dimitri, as they believe this is where he is hiding. They, however, find that it is heavily guarded and they get ambushed by Bostro and his cronies. Then Celeste comes from a hallway and saves Layton and company. Unfortunately it is later revealed that the scientists here weren't working on this machine but something of much more power. The project in question was Clive's Mobile Fortress.
It is also here Dimitri most likely worked on some of his earlier projects. These include Subject 3, Parrot (Subject 1), and possibly trying to return Claire to her original time. There is also speculation that Dimitri also worked on Beasly and he was once Subject 2. This is because Beasly is also able to talk and has some other characteristics. The one in question is how he is a quote "Puzzle Bee".
Later on in the story Layton, Luke, Flora, Future Luke, Don Paolo, Celeste, Inspector Chelmey, and Barton all meet up inside the Thames Arms. It turns out that the barkeeper inside the Thames Arms is also Dimitri, himself, in disguise. Layton, to prevent Dimitri form escaping, has a Puzzle Battle with him. Apparently, Dimitri has laced the building with explosives. However, this was actually a lie. Then Layton asks Dimitri for the reasons for his actions here as this can help unravel the mystery behind Future London.
Dimitri - "If my calculations were even the slightest bit off, I could be trapped forever."
Layton - "Then why take the risk?! What do you stand to gain?"
Dimitri - "Everything. You see, like you, Hershel, I loved Claire."
Layton - "So you intend to travel back through time and save her?"
Dimitri - "Surely you wouldn't stop me. After all, haven't you wished for this yourself?"
Layton - "...Nothing can excuse the kidnapping of all those scientists. Not even this Dimitri."
Dimitri - "You disappoint me. I had hoped a rational man like yourself would understand that the ends justify the means."
Layton - "I don't see it that way."
-Layton and Dimitri's conversation at the Towering Pagoda
Later on in the conversation, Dimitri explains the reasoning behind the kidnapping of Bill Hawks. This is his main reason for revenge.
After the conversation with Dimitri, Layton then tells all in the room the true mastermind behind everything about Future London. It is here Dimitri learns that he was actually a pawn in the main villain's plans. The main villain, Future Luke, then is revealed for the villain he tuly was the entire time. The "Luke Triton" of the future was none other than Clive Dove, a rich boy who lost his biological parents almost ten years ago and was adopted by Constance Dove.
After Clive unleashes his Mobile Fortress, Layton, Luke, Dimitri, Paul, Celeste, Chelmey, and Barton quickly escape the Thames Arms. To stop Clive and his destructive and deadly Mobile Fortress, Layton and co. knew that they must destroy the massive killing machine. The easiest way for them to destroy it was from the inside. So Layton uses his automobile to try and scale the massive fortress. Celeste then later uses Don Paolo's "goofy" Flying Machine to climb the all powerful Fortress of Madness. Dimitri and Chelmey also witness the machine take flight.
Layton and co. enter the generator room and save Bill Hawks. This then causes the Fortress to start destroying itself and Layton, Bill, Luke, Flora, Celeste, and Clive then escape the crumbling fortress. As the end of the game draws near Layton has one final conversation with Dimitri, Clive, and Celeste. When he is talking with Dimitri, Dimitri then reveals that Claire did not die in the explosion ten years ago.
He reveals that Celeste is, in fact, Claire, and she was shot ten years in the future to our present. However, he also explains that there were...complications. Her molecular stability was too weak, because part of her had been left in the past, so her body was trying to return. Dimitri did everything to try and stabilize her existence in the future, but Claire tried to stop him. Dimitri worked for ten long years trying to save her life. He was so close to achieving what so many called impossible that he was blinded by his own pride and love for Claire. So he could save Claire he decided to stop his research and "close the book on the time machine...forever". Then Claire finally goes back into the past; to the moment of the blast and ultimately died.
Dimitri, himself, doesn't give any particular puzzles. During the Layton encounter Layton (Don Paolo) makes up the puzzle "Looking Up". Then Dimitri's cage that he traps "Layton" and co. in houses the puzzle "The Right Button". As the Bartender in the Thames Arms that Dimitri poses as gives the puzzle "Diced Dates". Also at the Thames Arms, there is a Puzzle Battle given to Layton by him.
Dimitri has the same number of disguises as Don Paolo, master of disguise, in Professor Layton and the Unwound Future. His disguises are more realistic than Don Paolo's, though.
It is unknown if Dimitri went to prison with Clive after the events of the game.
Dimitri's fake first name, Alain, is pronounced the same way as his real surname, Allen.
Dimitri's fake surname, Stahngun, is a pun on the word "stun gun".
Dimitri may be named after Dmitri Ivaneko, a Russian physicist that contributed greatly to field theory (A field theory is a physical theory that describes how one or more physical fields interact with matter; this would influence greatly with the building of a time machine).
Though Don Paolo shared the same feelings for Claire as Layton and Dimitri did, there is no definitive proof Dimitri hasn't met him before the game.