So many ideas pop into my head it's sometimes hard to keep the story straight.
Harry had a surprise when he arrived back to the carriage after his morning flight around Hogwarts, the twins had succeeded much faster than anyone else in their animagus forms, apparently they felt the pull to their forms almost all the time and what shocked him more than anything else was that they both had a magical animal form. He had expected the Weasley twins to be monkeys, or raccoons, or other mischievous animals, but they defied his expectations and had each become a bright red Niffler, he was about to congratulate them on their success when they pulled him into an empty room.
Twin #1 "Greeting o Harry king of beasts!" he cringed "we the Niffler twins" he cringed even more "have a question,"
"ok I'll answer any question within reason if you lay off the puns!"
Twin #2 "agreed, we wanted to ask if it's normal to," Twin #1 "be able to speak to mice? and other mouse like creatures?" Twin #2 "because it was quite disconcerting when we snuck into the kitchens and a mouse asked us to get it some food,"
Harry chuckled, "yup perfectly normal, myself, Fleur and Brice can talk to anything that has wings, Mina can talk to anything feline, and apparently you two can talk to anything rodent like, did the mouse say anything else?"
the twins looked at each other, "well, it did ask us to help the happy bird, it's apparently sick or something?"
"Happy bird? what could that be?" Harry puzzled,
once again the twins shared a look, "well that's obvious, it's probably Dumbledore's phoenix,"
Having tried to ignore Dumbledore's existence Harry had no idea and so "... Dumbledore's WHAT?!"
After leaving the twins with orders to 'prank the living daylights out of Dumbledore' Harry took to the sky, he had a suspicion about what could be going on but needed to confirm it, if he was right he'd have to do something he really didn't want to. After circling the castle for a while he finally found the window to Dumbledore's office and hovered before it, he gently tapped the glass when he could see no sign of the headmaster, and from behind a bookshelf the head of Fawkes the phoenix appeared. Upon seeing Harry Fawkes flamed to the outside a few feet away and led Harry to an old stone arch that was build over the inlet for the lake, fawkes landed atop it and so did Harry who carefully changed back so as to not lose his footing.
It was a strange experience as Fawkes communicated with Harry, there were no words just impressions, feelings, and some images, it was then followed by a memory. Fawkes was close to a burning day and was very weak, Dumbledore had been tracking him for a while following him, even flame travel was not use as he was too weak to go far, as the fire consumed the weak old bird's body he could see through the flames the old man pouring a potion into the inferno and the loss of will Fawkes was forced to endure, only a little of his own will was left and it begged for help.
The small Hogsmeade Gringotts branch had received several more staff should Director Evans require assistance, but otherwise it was quite a small sleepy branch which was why the teller was surprised when the doors opened by themselves, but before the guards could react Director Evans appeared and stepped forward holding what looked to be a package under his arm that was still invisible.
leaning in close Harry spoke to the teller in a whisper, "I need the strongest flushing potion we have, a wit sharpening potion, half a pound of ashwinder ash, and a room protected from high intensity flames,"
the goblin simply said, "understood director, follow me,"
The room was quickly prepared as harry instructed, in the middle of the room was a single table as he had ordered the room to be empty of anything else, on the table were the supplies he had asked for. Harry mixed the ashwinder ash into the whit sharpening potion and the flushing potion, turning both into a fine paste which he began spreading over the still stunned form of Fawkes, he had to keep the phoenix stunned or it would be compelled to escape. He quickly finished what he was doing and ordered the room cleared, he gave instructions and two goblin guards stood behind him with their hands holding him while two others helt the door slightly open, just enough for him to cast through,
"sorry about this Fawkes, but there is no other way to free you... Avada Kedavra!" it took a lot of hate for Harry to cast the spell, he almost couldn't, he'd never be able to use it in a fight he just didn't have that kind of hate in him, as soon as the spell left his hand he was pulled back the doors were slammed and less than a moment later they began to melt under the tremendous heat, the corridor was quickly abandoned.
Director Ragnok was once again meeting his father King Rognok to explain why one of their branches had almost melted, he placed on the desk before his king a small nesting bed with an even smaller baby bird sleeping in it,
"This my king is Fawkes, who we though to be Dumbledore's familiar, now we know was his slave," Ragnok explained,
surprised and disgusted Rognok asked, "slave? how can that be possible?"
"Director evans sent an explanation, when this pheonix went through a burning day, that degenerate Dumbledore poured a love potion into the fire, anything else would have been burned away but a love potion is potent enough to still have an effect especially as due to the bruning Fawkes was too weak to defend itself," Ragnok explained,
"ah I see, so director Evans used the normal method for treating a phoenix?"
"he did my king, a flushing potion and wit sharpener mixed with ashwinder ash and applied before forcing a rebirth, director Evans has asked us to care for Fawkes as he fears that Dumbledore would try to re-enslave him otherwise,"
"and so we shall, by the way speaking of the director have we received the memory of the first task yet?"
Ragnok took the vial from his pocket and placed it before his king, who produced his pensive and they watched with great glee how Harry made getting past a dragon seem easier than purchasing a pint of milk.
Dumbledore was getting quite fed up, first he couldn't enter his office due to the door being turned into a giant dog squeak toy that was wedged into the doorframe, his robes turned jet black as soon as he entered the great hall, his dinner sprouted legs and ran away from him, Fawkes had gone flying somewhere and had been replaced by a rubber chicken, and he seemed to make a squelching sound when he walked, he was not amused although everyone else was, he was far too distracted to notice Harry had vanished for a few hours.
After sending Fawkes off Harry spent a few hours flying around the grounds trying to calm down, he had to stick to the plan he couldn't afford to hex Dumbledore's beard off. After cooling off he confided in Madam Maxine and Fleur who were both horrified about Fawkes enslavement, but got themselves under control when he assured them that old wrinkly nuts wouldn't be getting away with it, after all he had plenty of evidence against to old codger, all he had to do was bide his time.