While the rest of Hamelin slept, William slipped into the moonlit night. With the stars as his only audience, he made his way to the Tantalus River with his guitar slung over his shoulder. The familiar wood resting against his back and the ever-present rushing water welcomed him like old friends. Here, he could practice his music without fear of Father's judgment. Here, no one would hear him pour all his burdens into music.

Here, he was free.

But this time, he was not alone. Leaves crunched under Burdock's paws as he scampered behind William. The rat's ears twitched and his whiskers quivered as they made their way to William's usual spot, constantly on the lookout for any unwanted observers or potential predators who would eagerly devour a lone rodent.

Though he'd never imagined allowing anyone to follow him to his sanctuary of solitude, William was surprised to find Burdock's presence not only unintrusive but also welcome. Despite not being the same species, they were bound together by a shared desire to defeat the Piper.

William eased himself onto a fallen log, easing his guitar into his lap as he tuned the strings. "How is this going to work? I tried playing the Hymn of the Whole before, but the children didn't react well."

"I did not teach you how to properly wield the Hymn of the Whole before but merely told you how to see a small sample of its power." Burdock sat on his haunches and rubbed a paw over his ear sheepishly. "There is much I have not yet told you."

"You could have told me that sooner," William said drily. Misplaying the Hymn had led the children to attack him, leaving a myriad of bruises that still covered his legs and wrists in dark purple blotches.

"Not without putting you in grave danger," Burdock explained. "Imperfectly controlling so many listeners could easily lead them to harm others on your behalf whether you wished them to or not, to say nothing of how the Piper would react if he was alerted to your skill."

William shuddered. If the children hurt him so badly simply for misplaying the Hymn, he could only imagine the havoc they could have caused if they had attacked anyone who wasn't aware anything was amiss. "Fair enough."

Burdock twitched his whiskers. "Fear not, for I have done everything I can to ensure you can practice the Hymn safely."

William turned the last of his tuning pegs, giving the guitar strings an experimental strum to make sure the instrument was ready. "What do you have in mind for tonight? Should I just try to play what I remember again?"

Burdock shook his head. "I am not worried about you finding the core notes. Once heard, none with a musically inclined ear will ever forget them. But, as memorable as they are, they are nothing more than a skeleton for what we need. Played properly, the Hymn of the Whole is far more than its core notes. Only by channeling your feelings and desires into the Hymn can you harness its true power."

"You told me to only focus on the notes while I was playing it," William said. There was so much he didn't understand about how this strange song and how it worked. He was solely at Burdock's mercy.

"That is because I did not want to risk you damaging your soul." Burdock whipped his tail. "The benefits of the Hymn are many, but it can also be used to bind souls together. If you played it poorly, your soul could have become entangled with the children's, and you all could have lost yourselves in each other."

"You're taking quite a risk by letting me practice with you, then." William bowed his head. "Thank you."

"Do not thank me yet," Burdock said. "Do so after I have taught you how to wield the Hymn. First..."

Burdock's voice trailed off as he twitched his ears back and forth. William strained his ears listening for anything that could have distracted him, but only the roar of the Tantalus broke through the night.

At last, Burdock raised his gaze to meet William's, his eyes filled with determination. "First, you must remember that the Hymn of the Whole is fueled by two things: your emotions and your single-minded fixation on a goal. The goal will guide the listeners to carry out your bidding, provided they open their souls to you. Your emotions are what give the Hymn its power. Too little, and you will not be able to reach the listeners' souls. Too much, and they will be overwhelmed by your initial desire, making it impossible for you to control how they seek to carry it out, especially if you are attempting to control many listeners."

"The Piper must have complete mastery of the Hymn for him to control so many people," William noted. Burdock made controlling even one listener sound like a challenge, yet the Piper exerted power over Hamelin's children and all of Aerzen. What chance did he have against such a powerful foe with so little time to prepare?

"He is indeed powerful, but all is not lost," Burdock said. "Since our desires are simpler than a human's, rats are much easier to persuade to open their souls than your kind are. Likewise, human children are far more vulnerable than adults, especially when they are asleep. It is only by binding humans to the rats inside them that the Piper is able to control them so effortlessly."

"He nearly made me go to him," William said softly.

"You are a special case. The Piper focuses his song on the desire to be safe and cared for, and since your father treats you so poorly, that desire resonates with you far more strongly than it would for most humans, especially since your father's behavior has been escalating."

"I'll feel safer once the Piper leaves everyone alone." Not entirely safe, but he was used to dealing with his father.

"He will," Burdock said firmly. "All we need to do is weaken his control enough for more of the rats to openly resist him. Even one could be enough to inspire others to try to drive him away for the good of the Whole, which is why simply practicing the Hymn on me alone will make an excellent start to your mastery of it."

"I wish I didn't have to do it on you, though. It feels too much like..." William sank his teeth into his lip to stop himself from voicing the rest of that horrible, awful thought out loud. "It doesn't feel right."

Though Father didn't control him in the same way the Piper controlled the rats, he instilled such a deep, primal fear in him that he obeyed his orders all the same. Careless words about wishing he could devote himself to his guitar rather than the forge led to hours spent shoveling coal until darkness dyed his hands and smoke clogged his throat. Disagreeing with him over the slightest details led to cutting insults at best. Should he anger him badly enough, the burning bite of the belt...

William's throat tightened, his breath coming in gasps. Father would beat him bloody if he knew what he was doing, his reasons be damned. Not even the Lord above could save him if they were ever discovered. Father would drag him to the other side of the Tantalus where no one would be able to hear him scream and—

A sharp squeak broke William out of his trance. "I appreciate your concern, but I have thought long and hard about how best to begin your training." Burdock paused, waiting to make sure William had calmed down enough to listen. "We will start by having you guide me through a small, simple task. Humans can communicate by leaving markings on objects, correct?"

"Yes, but I'm not very good at it. I only know how to read the Book of the Lord." And he'd only learned that much thanks to the years he and the rest of the town had spent attending church every week. Only Pastor Abrams and Hamelin's few scribes who documented legal agreements and carried messages to other towns could read and write with ease.

"That will be sufficient for the task at hand. Think of a small, simple part of it. Do not tell me what it is," Burdock added quickly as William opened his mouth. "We must make sure you are truly controlling me completely and that I am not simply being influenced by what you have already told me."

"Okay." The most important word in the Book of the Lord only had four letters, the perfect size for their first practice session.

"Now simply play the Hymn of the Whole, channeling your emotions into it. Once my soul reaches out to yours, focus on what markings you would like me to create."

"How will I be able to tell what your soul feels like?"

"That is not something that can be explained with mere words," Burdock said. "You will know it once you sense it."

William nodded and positioned his fingers over the guitar strings. The first notes of the Hymn of the Whole emerged as timidly as a rat's steps out of its burrow, soft and tentative.

Burdock twitched his ears, a faint shudder passing through his fur. "Good. Now weave your feelings into the music so that they may become one with the Hymn."

William closed his eyes and leaned back. Under the soft light of the stars, the tension eased out of his muscles until all his body's aches faded to the back of his mind. The Tantalus washed away all his worries as if they were little more than pebbles. Here in his secret sanctuary, he was safe. At peace.

A faint presence brushed against the edges of his consciousness. Something small and warm, filled with memories of lapping fresh dewdrops from the fields at dawn and gorging himself on ripe blackberries until their sweet juice coated his fur.

No, not his fur. Burdock's.

William stroked the guitar strings as if his friend's fur was beneath his fingertips. The presence drew closer until its warmth bloomed inside William's chest, as beautiful and delicate as a newly blossomed flower.

Now to test their connection.

He began not with the whole word or even a letter but with a line. A single downward streak.

Tiny feet scrabbled over pebbles as Burdock searched the riverbank. That would not do. What they needed was further from the shore, under the cool shade of the trees.

Shifting stones gave way to crunching leaves. This was better, although William dared not open his eyes. They still needed something long enough to suit their purpose. Something hard.

There! The warmth in William's chest flared with satisfaction as teeth clamped onto the perfect stick. Burdock carried his quarry to William's feet, gathering a second piece of wood shortly after the first. One letter was complete.

Now for the second. They needed something curved, or at least something they could bend to their purpose. But the trees yielded nothing that would suffice. Their twigs were far too straight, too inflexible for what they needed. But what could they use? Perhaps...

William opened his eyes, his fingers still strumming the guitar. Reeds rustled along the riverbank, their thin stems bowing to the breeze. He scanned the shore in search of black fur or the flash of the rat's tail, but there was no sign of Burdock.

He couldn't have gone far. Surely it couldn't take too long for the rat to find—

Claws scraped against stones, punctuated by a sharp squeak of frustration.

William gasped as his eyes darted to the reeds waving wildly by the shore. They were shaken not only by the breeze but by Burdock biting and tearing at the long fronds, mere inches from the hungry current of the Tantalus.

Fingers slipped. A sharp squeak pierced the air as the discordant twang broke the Hymn of the Whole.

SPLASH!

The Tantalus swallowed Burdock's shriek of surprise as he fell into the river.

William struck the strings with all the blind terror he'd felt when he saw Emma march into the water alongside the other children. When the current had threatened to rip her away from him as he'd fought to swim through the sea of thrashing limbs. When water had seared down his throat, his mouth parted in a scream as blood gushed from his freshly broken nose.

He strummed so hard his entire body hummed with the Hymn's vibrations, tears burning his cheeks. He couldn't lose Burdock.

That same ball of warmth came to him again. Quicker this time, pulsing with the desire to expel the burning water from his lungs. To crawl ashore and collapse into a quivering heap. To survive.

But this time, Burdock was not alone.

Another soul glowed in response to the Hymn. Larger than Burdock's, it shined with all the warmth of the hearth on a cold winter's day.

The instant Burdock dragged himself onto the shore, William stilled his hand. As the last traces of the Hymn of the Whole dissipated into the night, so too did the brightness and warmth of the souls until all that remained was a lingering sense of closeness.

"Burdock!" William rushed to his side, slinging his guitar over his shoulder and scooping the rat into his hands. "Are you alright?"

"I believe so." Burdock trembled in his grasp, his black fur glistening with water. Slowly, the frantic staccato of his heartbeat eased until his breathing evened into slow, if labored, gasps. "I am merely unaccustomed to such an exertion."

William stroked his fur with trembling fingers. Nothing felt broken, yet visions of the Tantalus dashing Burdock's body against the rocks or sucking him beneath the current flooded his mind. "I could have lost you," he said brokenly. "I never should have let you talk me into using the Hymn on you. There has to be another way—"

"There is no other way!" Burdock snapped. A cough shook his tiny frame as he expelled water from his lungs.

"I'm sorry," William whispered. Burdock had trusted him, and he easily could have cost the rat his life. Some friend he was, too lost in his desperation to save Emma to keep his only ally safe.

A sigh brushed against his hand. "If I did not think it necessary to teach you the Hymn, I would have left you ignorant of it," Burdock said. "Were playing the Hymn easy, many more would try to claim its power as their own. This was a good first attempt, so I believe that with enough practice, you will be able to wield the Hymn without fear."

Unease swam inside William's gut. Though Burdock seemed unconcerned about the Hymn's effect on him, there was one doubt he could not leave unvoiced. "Did you feel the other soul too?" he whispered, his eyes scanning the riverbank for signs of any creatures that may have responded to his music.

"Yes." Burdock shook the water from his fur and began licking himself, with only his trembling whiskers betraying how exhausted his experience with the Tantalus had left him. "I do not believe they will interfere with our plans."

"Why?"

"Because if my suspicions are correct, the one who responded to the Hymn was your mother."