A/N: This chapter is mostly about setting up the plot of Prisoner of Azkaban since its important later in the story. It also remove the bit of angst between Harry and Hermione since its not what the story is about. :)

Harry was awake bright and early on the first day of September. He was impatient to be back to Hogwarts, even if he just had his best summer vacation of his life. Not only would he have access to one of the biggest libraries in magical Britain – something he knew would come handy for his many ideas – but he would also be able to do magic without having to lock himself in his room to remain unseen. With that in mind, Harry quickly shot out of bed and, after doing his morning route, changed and put a grey sweater and brown trousers. He then decided to finish his packing.

Most of Harry's possessions had already been put back in the various compartments of his trunk the previous evening, but some stuff was still left out. For instance, a few of Harry's clothes were laying on the chair at the desk, while the desk itself was nearly entirely covered with parchment scrolls, papers and even a small muggle notebook. Harry grabbed the notebook – which was full of ideas for his A.I. project – and put it in the pocket of his sweeter. The rest, he stored in the first two compartments of his trunk. Then, he grabbed the trunk and exited his room for the final time that summer.

Harry walked downstairs to the pub. It was rather quiet that morning. Tom, the owner of the Leaky Cauldron, was currently cleaning his counter. Around the room, a few witches and wizards were eating breakfast, some more quietly than others.

"Good morning, Mr. Potter." greeted Tom with a nod.

"Morning, Tom." said Harry, walking toward the counter. He grabbed something in one of his pockets before giving it to Tom. "Here is the key to my room."

"Thank you. Would you want breakfast this morning?" he asked, knowing Harry didn't eat breakfast every day.

"Of course." he answered, taking his money pouch. He put twelve sickles on the counter. "Same thing as usual."

"So, eggs and toasts for you." confirmed the older man, taking the coins. "Why don't you go grab yourself a table?"

Harry nodded and did just that. Taking the Weasleys into consideration, Harry sat down at the biggest table in the pub and waited for his lunch. Bored, Harry grabbed the notebook from his pocket and began reading his notes.

A.I Project: (Is the term "A.I" even approriate?)

Personality:

Male? - No

Female? - Yes

Naming ideas:

A.R.I.A.N.E. (A Really Important and Noticeable Executive) - No

M.I.A. (Magically Integrated Automation) - No

O.L.I.V.I.A. (Open Lifeform Imaged Variation Intelligence and Automation) - No

E.V.I.E. (Encrypted Virtual Intelligence Ensemble) - No

M.A.R.I.O.N. (Magically Advanced and Really Intelligent Operating Network) – Maybe, Lack familiarity.

H.E.D.W.I.G. (Highly Enchanted, Demure and Wholesomely Intelligent Guide) – Maybe, Would Hedwig be offended?

Features:

Interaction with flying broomsticks. (Include the monitoring of the charms and live data like speed, altitude, etc.)

Scanning and detecting surrounding magic (like Invisibility Cloaks, Glamours, Wards, etc.)

Possibility to take control over other magics and change its properties. (Magical hacking, basically)

Be able to talk, hear and understand words.

Be able to read. (A.I. that can learn by reading books by itself) (Via the scanning system?)

Interact on a magical level with other sentient magics (like a computer to another computer?)

Create projections and illusions and modify them at wish.

Store into memories rune sequences, ideas, etc for each broomstick project.

Things to research:

Look for books in the library.

Investigate magical paintings.

Investigate the Sorting Hat.

Harry closed the notebook and thought about his project. He wasn't sure where to start, really. He'd already done plenty of research in runes and charms for the enchantments but he hadn't found anything specific that could help him build his sentient, magical intelligence. It was the reason Harry had made a note to research magical paintings and the Sorting Hat. Both had their ups and downs.

Because of the sheer number of them, Harry doubted magical paintings were hard to make, nor did he think it would be complicated to find an instruction booklet – so to speak.. Unfortunately, magical paintings were nothing more than the imprints of someone, which is not something Harry wanted for his A.I. project. Also, as far as he was aware, paintings could only interact with other paintings and not anything else. The only exception seemed to be the Fat Lady who guarded the entrance of Gryffindor Tower.

His second idea, looking at the Sorting Hat, also had its problems. The Sorting Hat was very close to what Harry wanted to build and, if Hermione's favourite book Hogwarts: A History was anything to go by, it could also interact with Hogwarts and its various magics. However, the Sorting Hat was very unique and, as far as he knew, nothing similar had been done since its creation. It made Harry wonder whether the Sorting Hat had been enchanted with secret magic lost to time or not. There was also the possibility that the Sorting Hat would simply refuse to allow Harry to check how he worked. If either were the case, Harry might never be able to complete his project.

As Harry pondered once again on the question (it was something he had done a few times in the past weeks), he noticed someone walk down the stairs.

It was Hermione.

Consciously, Harry knew that he shouldn't have any feelings about Hermione's departure from their project other than a small sense of disappointment. After all, it was completely logical that Hermione decided to focus on her schooling rather than their extra-curricular projects. However, deep in his heart, Harry couldn't help but feel a pang at the knowledge he wouldn't be able to work with her anymore.

Harry saw a flash of regret cross Hermione's face when she saw him, and Harry had to stop himself from saying or doing... well, he didn't know.

"Good morning, Harry." she said, sounding slightly defensive and regretful. Damn, Harry could already feel some awkwardness and tension between them. He didn't want any of it. He knew the next few months would be very long if he and Hermione couldn't be alone without feeling like there was an elephant in the room. So, Harry shoved down any feelings he had developed the previous day and decided to greet her like he had done so many times.

"Morning, Hermione!" he said with a smile. "Not surprised to see you bright and early. We are going back to school today, after all." he teased. It must have worked because Hermione perked up, suddenly looking much more like her usual self.

"You're right! We're going back to Hogwarts!" she said with a bright smile, making Harry's heart flutter. "I can't wait to begin our new classes! I'm sure Arithmancy will be very interesting! I already read the whole book and the material was great!"

Harry chuckled. "Of course you did. Only you, Hermione." Hermione's cheek turned pink. "Not sure how interesting Arithmancy would be for me. I bought one book on it that summer but it failed to catch my interest. What I'm really waiting for is the Runes class."

"Of course." said Hermione fondly. "Learning runes to make more broomsticks?"

"As if you really need to ask." he said, making them both laugh. Shortly after, Tom arrived with Harry's breakfast before taking Hermione's order. The young witch ordered the same thing Harry was having and quickly received her plate. Harry and Hermione continued to talk for the rest of the morning, even after the Weasleys woke up and began preparing themselves to go to King's Cross.

Thirty minutes before the Hogwarts Express was due to depart, Harry, Hermione and the Weasleys left the Leaky Cauldron and went to the station in Ministry vehicles. Harry realized rather quickly that the cars the Ministry loaned were most likely there to ensure his protection in case Sirius Black tried something.

Because of the traffic, the Ministry cars did not arrive to King's Cross Station until 10:50AM. The group quickly grabbed their trunks and their pet cages before running through the station, hoping to make it in time. When they arrived to the barrier, Mrs. Weasley went first with Ginny, followed by the twins, then Percy and Hermione, Ron and Harry and, finally, Mr. Weasley.

Hermione, Ron, Percy and the twins quickly entered the train. Harry made to follow them when he was stopped by Mr. Weasley, who put a hand on his shoulder.

"Harry, before you go, can I talk to you quickly?"

"Uhh – sure, Mr. Weasley." answered Harry.

Mr. Weasley led Harry toward one of the pillars in the middle of the platform before he began talking to him. "Harry, did you hear about Sirius Black?"

"The mass-murderer who escaped Azkaban?"

"Him – yes." said the balding redhead. "Molly doesn't want me to tell you since she feel it would put pressure on you and stress you, but I believe you deserve to know for your own safety. Sirius Black was one of You-Know-Who's greatest supporters. He is said to be He-Who-Must-Not-Be-Named's right hand man. When your family was attacked back in 1981 and You-Know-Who was vanished, Sirius Black went crazy and murdered a bunch of people. We, at the Ministry, believe that Sirius Black lost everything when You-Know-Who was defeated. Because of this, we fear that Black might attempt to take revenge on the person he would see has having wronged him and his master..."

"Me." finished Harry. Mr. Weasley confirmed with a nod. "I already suspected it once," said Harry "I learned about the murders Black did a few days after Voldemort's attack. I thought it might be a possibility."

"It is. Because of this, I want you to promise me you will do your best to remain safe while at Hogwarts." said Mr. Weasley.

"Sure. I promise." said Harry.

A hint of something crossed Mr. Weasley's face, almost as if he knew something Harry didn't. "I also want you to promise me that – whatever you might hear – you won't go looking for him."

Harry blinked. "What?" he blurted, hardly believing what he had heard. "Why would I go look for someone who want to kill me?"

"Promise me, Harry."

"I won't." he promised, still not understanding what Mr. Weasley was saying.

"Thank you." said Mr. Weasley with relief. "Now, you better go before the Hogwarts Express leaves without you."

Harry nodded and walked away. He entered the train just before the doors closed. He went to search for his friends.

It took a few minutes but Harry found his friends in one of the last compartments of the train. Surprisingly, they weren't alone. With Hermione and Ron was a sleeping wizard with shabby grey robes. The wizard was on the same side of the compartment as Hermione and leaning on the outside window. Ron was sitting on the seat opposite of them.

"Who's that?" asked Harry quietly.

"Professor R.J. Lupin." answered Hermione.

"How do you..." he started but Hermione interrupted him.

"It's written on his case." she answered sharply.

Harry looked at the case, then back at Hermione. "I meant how did you know he's a professor? It's not written on his case."

Hermione shrugged. "Educated guess."

"If you say so." said Harry, sitting down on Ron's side.

"So, what did Dad want to talk you about?" asked Ron.

"Apparently, Sirius Black might be after me because I defeated his master." answered Harry.

"That's horrible!" gasped Hermione.

It was Harry's turn to shrug. "That's how my life works. Nothing I can do about it but make sure I'm safe." he said. "Let's just change the subject. I don't want to talk about it."

It seemed to remind Ron of something because he suddenly started to talk animatedly. "Harry! I forgot to tell you yesterday but with the money I made from the Robin deal, I bought myself my own wand!" he exclaimed before showcasing it to his best friend. It was a rather long wand made of a pale wood.

"Was about time you had your own." said Harry with a smile. "What's it made of?"

"Willow for the wood and unicorn hair for the core! It's fourteen inches long."

"Fourteen inches!?" asked Harry in disbelief.

"Fourteen inches." confirmed Ron proudly.

"Your wand is so long!" gasped Harry. "It's longer than mine! I'm so jealous!"

"I know, right?" said the redhead, trying not to laugh.

"The length of your wand is impressive! It's above average! I'm sure a lot of girls would give you hungry looks if they knew that!" he exclaimed. When Harry and Ron's eyes met, they couldn't keep it anymore, and burst out laughing.

Hermione immediately tried to shush them. "There's someone sleeping here!" she hissed. When Ron and Harry quieted down, she rolled her eyes and muttered "Boys."

"Jokes aside," said Harry. "It remind me that I have yet to pay either of you for your work on the Ravenstar." he said.

Ron yelped. "I haven't done anything on the Ravenstar! I didn't even test it!"

"It's your hindsight on the Mark II prototype that allowed Hermione and I to decide where to focus our efforts. So, please, don't fight it." he said.

"Fine." grumbled Ron half-heartedly.

"Now, I just have to figure out how much to pay for the 'salaries'. I can't just divide the profits in three since the company need to make its money too to pay for things like development, extensions, parts and other stuff like that."

"How much money do the Ravenstars sell for?" asked Hermione.

"20 galleons. After the expenses of production and the division of the profits, we make 5 galleons of profit for every broom." He thought about it for a few moments. "I guess what I could do is pay each of you one galleon per Ravenstar sold. It's not much, but the brooms don't cost much either." he said apologetically. "I'll make the pay bigger when we start selling more expensive brooms."

"That's fine." said Hermione. "It's not like we really need the money. We're still young, only thirteen-years-old, so we don't have to worry about it."

"It does make for some nice spending money, though." said Harry with a smile.

"When will you begin developing the Mark IV?" asked Ron.

Harry shrugged. "I've started around the time of my birthday, but it wasn't my main focus. I also began working on a separate, non related project – though I haven't made much progress on that front. For the Mark IV, my goal is to have a completed, finished product at the end of November."

"So soon?" he asked. "Why?"

"I made plans with Mr. Widdershins – the owner of Quidditch Quality Supplies – to have a broom ready to sale in mid-December. We even signed a contract on it."

"A contract?" asked Hermione sharply. "What contract?"

"A basic contract that say that both the expenses and profits will be divided 50/50 between each party – which reminds me. I'll have to send half of the parts to Mr. Widdershins once we're back at Hogwarts so that he can pay for them. I told him I would get the parts, you see." said Harry. "As for the production, it's also divided 50/50. Since we plan on having 60 broomsticks available before launch, I'll have to enchant 30 of them."

"You'll let the shop enchant the others?"

Harry nodded. "Yes. That part of the contract is very similar to the one we signed with Hogwarts. Basically, Quidditch Quality Supplies will have the rights to use our rune sequences and will enchant their half of the broomsticks themselves but they won't have the rights to the rune sequences themselves. They also won't be able to modify them without legal repercussions."

Hermione nodded. "You seem to have done well." she commentated, impressed.

"I don't know if I should be happy or hurt you seem surprised." teased Harry.

"Of course not! I knew you could do it." said Hermione, backtracking with a blush.

"Of course you did." said Ron, rolling his eyes.

Once they finished talking about the Potter broomsticks, the three friends quickly came to do their own things. Hermione grabbed one of her books on Arithmancy while Ron and Harry played a few games of wizarding chess. Once Harry had been beaten five times in a row, he forfeited, calling Ron the king of chess. With Hermione reading and Ron quickly falling into light sleep, Harry grabbed a pen and his notebook and wrote in a few more ideas he had.

As the time of day progressed forward, the weather changed. While it had been sunny in London, it was now raining hard outside of the train. In the silence of the compartment, all that could be heard were droplets of rain hitting the windows. It was sometimes accompanied with Ron's light snoring, Hermione turning pages of her book and Harry writing words in his notebook.

Thirty minutes before the estimated arrival of the Express, the train began slowing down. Ron wake up with a snort. "Are we already there?" he asked with a yawn.

Hermione frowned. "We shouldn't. We're thirty minutes early."

"Maybe the wind was in the right direction to help us." said Harry, looking through the window.

"That's not how it works, Harry. The Hogwarts Express is magical. It's enchanted to arrive at a precise time. Even if it wasn't the case, I doubt wind – no matter how heavy – would be able to affect a long, heavy train. It's not like a broom, you know."

"I guess you're right." said Harry, closing his notebook and putting it back in his pocket. "Why are we stopping, then?" As if to answer him, the train suddenly broke hard, sending Harry and Ron flying. Then, the lights around the trains flickered before going out. They were suddenly plunged into total darkness.

"What's happening?" blurted Ron. He and Harry were trying to raise back from the floor. It was a challenge since they could barely see anything.

"I don't know!" said Hermione with a hint of panic.

"Ouch!" exclaimed Harry. "You just stepped on my hand!"

"Sorry!" said Ron, managing to raise on his feet.

Harry followed suit and tried to find his seat. He felt completely blind. Believing his seat to be in front of him, he turned and sat down. He immediately shot back up when he heard a small gasp. He had just sat on someone! "Sorry!" he said.

"That's fine..." said Hermione.

'Of course it had to be her' thought Harry with embarrassment. Tired of not knowing what was where, Harry grabbed his wand. "Lumos." he whispered. As he had discovered, he was facing the wrong direction, the seat where he had been sitting being in front of him. He was just about to reclaim his seat when he noticed the shabby-looking professor wake up in the corner. He seemed to take one look around before shooting to his feet. "Sit down and stay quiet." he ordered with a hoarse voice, a bit of mist coming out of his mouth.

Harry reclaimed his seat before realizing what he had just seen. Mist? He was just now noticing how cold it had become. In front of him, Hermione shivered slightly, rubbing her arms to give herself warmth. "What's going on, professor?" she asked.

"If I'm right, nothing good." said Professor Lupin. The professor conjured a small ball of fire in his left hand and grabbed his wand with the other. Before he could reach the door and open it, a shadow appeared in the hallway. The professor immediately stilled. Harry looked on in horror as a large, hooded figure appeared on the other side of the door. The figure extended a rotten hand toward the door of the compartment and wandlessly unlocked it. The door began sliding open.

The most intense cold Harry had ever felt swept the compartment. The creature glided through the doorway. It seemed to look around the compartment.

"None of us is hiding Sirius Black under our cloaks. Go." said Professor Lupin. The creature ignored him. Then, it drew a long breath.

Harry's vision began turning black as the cold began chilling Harry to the bones. He felt like he was drowning. His eyes rolled up his head. The last thing Harry heard before blacking out was a the foreign – yet strangely familiar voice of a woman yell his name.

"HARRY!"

"Harry..."

.

.

.

"Harry, wake up!" said a female voice.

.

.

He felt a sharp sting on his cheek.

.

"Ron! Don't slap him!" chastised the female voice. Harry opened his eyes.

He found he was in the compartment of the Hogwarts Express. Why had he fainted?

"Harry!" exclaimed Hermione with relief.

"What happened?" he groaned, sitting up from the floor.

"You fainted, that's what you did!" said Ron. "When the creature started sucking air, your eyes just rolled back! I thought you were having a seizure or something..."

Harry blinked. He now remembered what had happened – what the horrible creature had done to him. "What happened to it? The creature?"

"Professor Lupin used a spell to push it back." explained Hermione. "It was like a bright, silver shield. The creature let out a small cry of pain before gliding away."

"And what was it?"

"Professor Lupin said it was a dementor."

"Dementor? As in the Azkaban guards?" gasped Harry. Hermione nodded. What were dementors doing in a train full of children? Did they really expect to find Sirius Black here? "How long was I out?" he asked.

"Five minutes." said Ron. "We should arrive back at the castle in twenty-five."

"Thanks." said Harry. "Did the professor say anything before he left?"

"He did!" exclaimed Hermione before grabbing something that had been lying on the seat next to her. It looked like it was a small, thin package wrapped in tin foil. "Professor Lupin told us to give you this once you woke up. It's chocolate. It will make you feel better from the dementors." she explained at the look he gave her.

Harry grabbed the small package and unwrapped it, finding half a bar of milk chocolate. He broke off a square and ate it. Almost instantly, he felt a wave of heat that helped dissipate the remaining cold from the dementor. "Wow." he said, munching on his chocolate.

"I know, its great, right?" said Ron. "Never say that chocolate isn't healthy for you, because this prove otherwise!"

Hermione rolled her eyes. "Ron, it's not because chocolate cure you from dementor exposure that its healthy."

"Try to convince me otherwise." he said before grabbing a chocolate frog from his pocket. As a show of defiance, he ate it while staring in her eyes.

"Ron, chocolate is full of sugar! It's not healthy!"

"Say the dentists' daughter!"

Harry rolled his eyes in exasperation and tuned out their argument. He was grateful they weren't making a big deal of his fainting spell. He couldn't help but hope it was the last time he would encounter a dementor.

As it turned out. It wasn't.

When the Hogwarts Express arrived to Hogsmeade, Harry, Ron and Hermione quickly disembarked and went to the chariots. When their chariot approached the gates, Harry was horrified to see a dementor posted on each side.

"Please don't tell me they'll be guarding the school." he whispered to himself.

When they arrived at the castle, the trio of friends quickly made for the Great Hall. Unfortunately for Harry, Professor McGonagall stopped him and Hermione before leading the two to her office where Madam Pomfrey was waiting. The healer quickly examined Harry despite the boy's protests and tried to give him chocolate. Harry stopped her before she did, explaining how he had already eaten some. Madam Pomfrey praised Professor Lupin before letting him go. Hermione was kept behind, to Harry's curiosity. He only had to wait a few minutes before Hermione exited the office, smiling.

"What got you all cheered up?" he asked.

"Oh it's nothing." she said quickly. Harry detected a lie.

"It's clearly not nothing, Hermione." he said.

"Please, Harry..." she pleaded. "I can't talk about it."

Harry looked at her. "Alright. I know you wouldn't keep something secret from us unless it was important." he said, making the girl smile at the show of trust. "Let's go to the Great Hall. I'm hungry and I don't want Ron to eat all of the food." Hermione chuckled. Harry and Hermione entered the Great Hall just in time to hear the headmaster begin to talk. They quickly and discretely made to the Gryffindor table and sat with Ron.

"Before we begin our succulent feast, I wish to say a few things. First, I would like to announce the changes of our staff. For Defence Against the Dark Arts, the post of teacher previously occupied by Professor Lockhart will now be filled by Professor Remus Lupin. As for Care of Magical Creature, it is my unfortunate duty to announce that Professor Kettleburn has retired at the end of last school year. From today onward, he will be replaced by non-other than our own Rubeus Hagrid! Let's give a round of applause to welcome Professors Lupin and Hagrid."

Not many students across the Great Hall seemed excited at the sight of the new professors. Harry, Ron and Hermione were the loudest of the cheering bunch. Up at the staff table, both professors looked embarrassed at the applause. While Professor Lupin managed to keep his composure, Hagrid did not. His face was bright red.

"Yes – welcome professors." said Dumbledore. Then, his tone changed to grim. "I'm sure you must be all aware by now, but the school is currently playing host to some of the dementors of Azkaban, who are here per the Ministry's orders. The dementors are stationed at every entrance to the grounds and, while they are here to protect us, I must warn you all. Nobody here is to make it out of school without permission." he said, making Harry freeze.

Harry knew he most likely would have to go the Ministry to do some paperwork before the launch of the Mark IV in a few months. He hoped the dementors wouldn't stop Dumbledore from letting him go.

"Fortunately, or unfortunately depending on your point of view, dementors cannot be fooled by tricks and disguises. There is no point to make yourself invisible, scentless or soundless – the dementors will still be able to detect and find you." said the headmaster with a glance toward Harry, Ron and Hermione. "It is not in a dementor's nature to understand pleading or excuses. I must therefore warn each and everyone of you not to give a dementor a reason to harm you. Do not go seek them, as it might be the last thing you'll ever do."

Harry, Ron and Hermione looked at each other. They had never seen the usually cheerful headmaster look or speak so grimly. It really showed them how serious business the dementors were.

"On that note, I believe we are all awaiting the most exciting part of the feast... well, the feast." said Dumbledore before clapping his hands once. Massive amounts of food immediately appeared on each of the tables.

As his friends began to serve themselves, Harry thought back to what Dumbledore had said. Dementors were going to be around Hogwarts, guarding the borders of the grounds. This was bad news for Harry since he expected to spend a lot of time outside testing his brooms. What would happen if a dementor wandered inside the grounds and found him? Unlike Professor Lupin, Harry did not know any spells that could protect him. His only option would be to run away. To have enough time to do so, Harry would need to be warned if a dementor approached.

Harry grabbed the notebook in the inside pocket of his school robes and quickly wrote his latest idea.

Detect Dementors!

A/N: The name "H.E.D.W.I.G. for the A.I. comes from a review by .