"The wand chooses the wizard. That much has always been clear to those of us who study wandlore."
Mr. Ollivander was a brilliant wand specialist, but even he did not know everything. While it is true that it is not the wizard who chooses the wand, the wand does not choose the wizard either. The Wandohrers that inhabit the wand do. Wandohrers inhabit trees that are harvested by wandmakers and hope that they will be lucky enough to have the branch that serves as their house plucked by a wandmaker to be fashioned into a wand. If they are so lucky, they choose a witch or wizard whom they deem to be powerful to become their master. Once they claim a master, their life becomes tied to that of their wand's owner. If their master dies, so do they. They are laid to rest with their master. However, if another wizard defeats their master, they will switch allegiance. Power is prized above all else to Wandohrers, and if another wizard proves to be more prodigious, they will serve that person instead. Thus, they do not die even if this witch or wizard defeats their previous master by killing them. Witches and wizards still do not know of the creatures that are truly responsible for the extent of their magical powers. It is unclear as to whether or not Wandohrers know that they are not receiving due-credit, or if they are aware yet simply don't care.
Wandohrers live very single-minded existences; their only goal having their home fashioned into a wand so that they may live in a wand, pouring their powers into it when it is being used to do its master's bidding. It is because of a Wandohrer's allegiance to its master that a wand produces inferior magic when it is being used by someone other than its master. Wandohrers live very isolated existences. Though there may be many that inhabit the same tree, they do not socialise very much. They care only about being selected. However, as with any species, there are always the exceptions; the beings that don't quite fit the mold. Such was the case with the Wandohrers Wilimena and Walt.
The two met on the main drag of their branch. Each lived in a thin branch that extended from the thicker one where they met. Right away, each knew that this encounter was not going to be the normal, friendly yet brusque nod at a fellow Wandohrer. The two instantly connected; there was no other way to describe it. When Walt looked at Wilimena, he didn't see what others saw. Humans would have mistaken her for a speck of dust, and other Wandohrers saw just another one of their kind with the same knobby brown face, bright blue eyes like chips of ice and tiny pointed white teeth. Walt however, saw her passion and joie-de-vie that she exuded like a tangible, physical quality. It could be seen in the way she held herself and engaged with others.
The two connected instantly and soon struck up a deep friendship that quickly translated into something more. Unlike all the other Wandohrers who tried to spend as much time as possible isolated in their respective home-branches so as to maximise their chances of being plucked by a wandmaker, Walt and Wilimena spent a great deal of time together, enjoying one-another's company and dating. They also spent an equal amount of time plotting ways to avoid being chosen so that they would not be separated. Their love had become so strong that their desire to stay together outweighed their desire to fulfill their destiny. Unfortunately, destiny is something that cannot be avoided.
One day when Wilimena was taking an afternoon nap in her holly-branch home, the renowned wandmaker Ollivander was out selecting some branches from which to fashion some new wands. As he waved his fingers over the branches trying to determine which were most fitting for that particular day, he was drawn to a specific branch on his holly tree. It seemed to be emitting some particularly strong magical vibes.
"Ah! I'll take this one," he thought to himself as he carefully separated it from its mother tree.
Wilimena gave a cry that Ollivander had no hope of hearing. It was not the expected cry of exultation and triumph, but a heart-wrenching scream of anguish. She realised that what she had feared most was happening.
"Walt! Help! He's taking me away from you!" she cried, hoping that he would hear from his neighbouring yew tree.
As luck would have it, Walt heard his love's cries and desperately began casting magical vibes every which way. He had no solution to their predicament, but was hoping that by some miracle he would be overcome by powers strong enough to free Wilimena.
His magic did catch Ollivander's attention, and the wandmaker gleefully went to take the yew branch as well, knowing that it would harvest great power. With his two prizes in hand, he turned to make the trek back to his shop where he would fashion the wands with the two phoenix feathers he had just obtained.
xxxxx
Hours later, Ollivander sat back with a sigh of satisfaction and studied his work with great pride. Before him lay two gleaming wands that whispered of great magic. His brow puckered with slight confusion however, as there was something that felt just a little bit different about the two. They seemed to possess some unusual connection. He couldn't quite put his finger on what it was, but he knew that he would keep a close eye on these two and try to figure out the mystery.
Years later, his suspicions were confirmed. What were the odds that He-Who-Must-Not-Be-Named would be chosen by one of the wands, and the Boy Who Lived by the other? Ollivander took a particular interest in the story of Harry Potter, and his suspicions grew as it became clear that when fighting against one-another, the wands behaved abnormally; seemingly unwilling to destroy each other. Ollivander determined that it must be the phoenix cores that the wands shared, as that was the only apparent connection. Little did Ollivander know that there was a pair of Wandohrers that also connected the two wands, and that Walt and Wilimena were in fact behind the abnormal behaviour.
On the night in the graveyard when Voldemort's wand connected with Harry's, the two Wandohrers were the only two beings in the graveyard who did not feel fearful in that instant. Instead, they felt joyful because for a few instances, they were finally reconnected. That quickly ebbed away and was replaced by horror when the two lovers realised that their owners' sentiments were the complete opposite of their own, and that they were in fact bent on destroying the other. Knowing that if one wizard were to destroy the other, their lover would die as well, Walt and Wilimena threw all their energy into fighting their masters' wishes when he was trying to destroy his nemesis. Instead of using their power to enhance their masters' magic, the little Wandohrers would seek to do the opposite.
Upon hearing from Harry what had happened that night, Dumbledore drew the same conclusion that Ollivander had come to. He coined the phrase "brother wands," to describe the strange relationship that the yew wand shared with the holly one. Yet in a rare turn of events, Albus Dumbledore was wrong. It was neither the shared Phoenix cores nor a brotherly bond that caused the connection, but a powerful romantic love shared between two tiny but powerful creatures. A wise person once said that it is the people you least expect who do the most incredible things. Such was the case here. Creatures that could not be seen by the naked eye; that the wizarding world did not even know existed; greatly impacted the events controlling their world, even playing a key role in bringing about Voldemort's demise.
It was not such a happy ending for Wilimena and Walt. The constant strain of trying to protect Wilimena took its toll on Walt's health, weakening the yew wand's power to such an extent that it was eventually destroyed the night the Order rescued Harry from the Weasleys, killing Walt as well. Wilimena mourned her lover's death for the rest of her long life. Finally, when the Boy Who Lived had had his deservedly long life and had peacefully been laid to rest, Wilimena too passed on to whatever came next...hopefully to someplace where Walt was waiting for her.