***

Until now, Hisa had thought herself patient. As she practiced turning herself into mist, though, only to grow dizzy, reform and stumble, worries about Megumi nagged at her. What was Sota telling her right now, about her disappearance? How was he treating her? Spurred on by these fears, she pushed herself, and staggered once more.

"If you need to rest, I won't blame you," Shiroko reassured her.

Jaw clenching, Hisa stood. "I can't. I have to keep going for Megumi."

With that, she tried again, willing her body to evaporate. It was the most disorienting experience she'd known. Somehow she could still see and hear, but couldn't shake the dread that if she lost focus, she'd disperse into nothing on the breeze.

Once she'd gotten a decent grip on her brumous form, it was time to practice altering her appearance, to pass for human as Shiroko had done that day. She bent over a frozen lake, visualising her former appearance. Taking on mortal guise proved much easier than evaporating, like slipping into worn yet comfortable clothing; her features shifted into familiar ones, hair fading to grey, deep lines etching her skin. Colour flushed her cheeks, and there wasn't a frost crystal on her body in sight.

After she'd changed from her youthful self to her elderly one and back several times, she saw Shiroko's reflection nearing.

"Would you say," her new mentor asked, "you're ready to do this?"

Turning round, Hisa gave a resolute nod.

***

If the situation hadn't been so fraught, Hisa would have marvelled at how effortless the walk – or rather, drift – was. She'd almost forgotten was it was like to move without her hips and lower back protesting. Before long, the satoyama came into view, the fields mostly empty of produce and glazed with a thin crystalline layer. At the centre stood the straw-insulated hut. A house that was no longer a home.

Silently, they made their way up the path. Hisa took a deep breath of frigid air, and evaporated into it, seeping under the rickety door and reappearing inside the hut.

Gasps and yelps greeted her, as did two stunned faces. Sota staggered back. "Who are you," he demanded, "and what are you doing in my home?"

Hisa let her youthful features shift into aged ones he knew all too well. "Our home, you mean."

Sota stood rooted to the spot, mouth open. It was Megumi, through her tears, who spoke up.

"Grandmother!" The ten-year-old ran forward. "Father said... He said there was an accident, you fell..."

"Get away from that creature." Sota grabbed Megumi's arm, pulling her back so hard she toppled and cried out. "That isn't your grandmother. That's an impostor, a trickster spirit." Visibly trembling, he kept his glare on Hisa. "Whoever you are, why must you mock us at a time like this?"

Ignoring him, Hisa ran to Megumi and helped her up. As she did so, she hummed her usual song, the one that had always brought her granddaughter comfort.

Megumi stared and blinked. Her bewildered expression gave way to a grin of pure joy. "It's really you! Father, it is her, she's back!"

Hisa returned the smile. "I'm not going anywhere just yet."

She turned her attention to Sota, whose face contorted into a scowl, even though he didn't dare approach. "Don't fall for her tricks," he warned, with the waver of someone denying the truth.

Taking on her younger, taller and less human form, Hisa drew closer to her son, making him back against the wall. "I don't care what happens to me," she said. "But I do care what happens to Megumi. And you won't lay another finger on her as long as I'm around to watch over her." Glancing at the closed door, she raised her voice. "Or as long as others are."

On cue, white fog billowed from under the door and solidified into Shiroko, earning a cry of recognition from Megumi. "You heard her." Shiroko's words cut through the air, which chilled around her. "Try anything, and we'll know." They wouldn't, necessarily. It was already obvious to Hisa that yokai weren't all-knowing. Still, the threat appeared to convince Sota, who cowered.

She turned to Megumi, her form wrinkling back into the one she'd had throughout her final years as a mortal. "If you want, you can even come with us. There's a place in the woods where you can live. If you'd rather stay here, I'll understand, but..." Her gaze slanted towards Sota. "Remember our warning."

The fear hadn't entirely left Megumi's eyes, but her face lit up. "I can leave this place?"

Sota brought himself to inch forward. "I'm not letting you take her!"

"We're not taking her," Hisa replied, keeping her tone steady, reminding herself she didn't have to be afraid of him anymore. "We're giving her a choice."

Megumi glanced from Hisa and Shiroko to her father, then back, before speaking up. "I'll do it. I'll come with you."

At her words, Sota slumped against the wall. "Megumi... How can you be so selfish? I thought your grandmother gone. Now you're going to abandon me too?"

Hisa wanted to ask him how he liked being abandoned, but thought better of revealing the truth to Megumi just yet. Instead, she echoed his words to her. "Don't fall for his tricks."

Megumi clenched her fists by her sides. "I'm sorry. But I can't stay here."

Tentatively, Hisa slipped her arm around her granddaughter's shoulders. Her touch would surely be colder now than it used to be, and she felt the child's muscles tense, but they quickly relaxed. "Then let's go."

As the three headed away, Hisa cast one more look behind her. Sato sagged to the floor, head drooping as he held back tears, his anger cooling to resignation. His reaction brought on a pang of guilt, of maternal instinct to somehow lessen the damage, but as she opened the door, she reminded herself of the harm he'd done Megumi. Harm he wouldn't get to do again.

The plan wasn't without its risks. Shiroko had hinted earlier at some yokai being as dangerous as the stories said, and the thought terrified Hisa with each step into the woods. Still, she knew deep down that Megumi would be better off here than back in her old home. Some monsters, after all, were human.

With each passing day she and her granddaughter spent in the woodland village, the more at ease she grew. Local kitsune guarded the clearing with illusions created to confuse humans, so they'd find themselves back at the forest's edge. And one thing was certain. If anyone did try to hurt Megumi, they'd have to answer to Shiroko, one of the oldest and most powerful spirits of these mountains.

Time went by, blossoms growing and falling from the trees spread out at the mountain's base, followed by leaves. Sometimes Hisa would venture from the dwelling and pass by the satoyama, glimpsing Sota hunched over the crops. By the look of it, he never married again or fathered any more children, wallowing in his self-pity alone.

And Megumi, as she grew, found herself faced with another choice. Shiroko had explained what it would entail, that she'd mature to her prime, then become ageless. As sought after as immortality was, some people ended up resenting it.

It was one winter that she stated her decision. "I'm ready." In the middle of the clearing, she approached Shiroko, her feet leaving prints for the last time. "I've been vulnerable for too long. I want to be strong, like both of you."

Mixed emotions coursed through Hisa. The fears for her granddaughter never fully ceased, but a smile spread across her face. The elderly, wrinkled face she chose to wear all the time, since it was the one Megumi knew, albeit with a dusting of frost to show that she embraced who she was. "If you're sure," she said, "then you have my blessing."

With a tender gaze, she watched Shiroko settle her hands on Megumi's shoulders, the girl's form rippling at her touch as mist swirled around her. Just as Hisa had once done, Megumi was now closing the door on her old life, embracing the new one the mountain guardian had granted.