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Stiles sneezes all over Derek's abs. Derek rolls his eyes and wipes himself down with the bedsheet.
“I told you not to overexert yourself pulling up that spring. What the hell do we need a swimming pool for anyway?”
“To swim in, obviously,” Stiles snaps, swiping at his nose. “Why am I sick?
Derek sighs and rolls out of bed. “I'll get you something to drink. Stay put.”
Stiles is splayed out on the bed when he gets back with a mug of honeyed tea. “Why am I sick?” Stiles whines.
“Because. Drink your tea.”
Stiles drags himself up the bed and huddles against the headboard, planting his naked butt right on Derek's pillow. Derek sighs. As much as he loves Stiles, he doesn't actually want to sleep on a butt-smelling pillow all night, not even when the butt-smell is Stiles' butt-smell.
Stiles takes the mug from him and takes a tiny sip, scowling mightily. “It's hot.”
“That's the point. Shut up and drink it.”
“Fine, jerk.”
Stiles sips his tea in total silence, giving the wall his best thousand-yard stare. The quiet gives Derek the heebie-jeebies. He caves like a coal mine.
“Alright,” he grunts, sitting on the edge of the bed. “What's up?”
“I'm not supposed to get sick,” Stiles says, curling his knees up to his chest.
“Everyone gets sick.”
“Not forest spirits. If our forest is healthy, then we're healthy. So if I'm sick, then that means-”
“The forest is sick.”
Stiles nods, sipping from his mug. Derek looks out the window at the forest, which looks as healthy as it's ever been, which is healthier than it was before Stiles settled in.
“So how do we heal it?” Derek asks.
The muscles in Stiles' cheek jump as he clenches his jaw. “We go to the infection site and carve it out,” he answers, his voice uncharacteristically tight. Derek feels a curl of apprehension at his tone but nods, trusting Stiles to know what's necessary.
The infection site is on the very southeast edge of the forest, and far enough out of the way that they end up hiking the two days it takes to get there. Stiles is eerily quiet for much of the trip, for all that he pretends to be fine, and there's an ill-fitting hardness that creeps onto his face when he thinks Derek can't see him.
The heat of midday is just beginning to cool into evening when Derek first sees the dying trees. It's a small ash grove, no more than twenty-some trees, and it reeks of decay.
Stiles touches the trunk of the closest ash. “Emerald Ash Borer,” he says, laying both hands on the trunk. He frowns up at the canopy, or rather, what's left of it. “They're not supposed to be here.”
Derek looks at one of the dead ash trees where a strip of bark has fallen away. The surface is a maze of trails where the beetle larvae have chewed paths through the trunk. “What do you mean?”
“They're not supposed to have spread to California yet,” Stiles answers. He begins winding his way through the grove, laying a hand on each of the ash trees to check its condition before moving on to the next. His expression gets progressively blanker as he makes his way through. “I'll have to put out word to the neighboring forests and the Forestry Service to check the ash trees. These ones have been infected for a while.”
Derek nods once before stripping off his jacket and shoving his sleeves up to his elbows. “So what's the plan?”
“Like I said before,” Stiles' voice deepens as he shifts to his natural form. “Carve it out.”
This is only the second time that Derek has seen Stiles' natural form, and watching the shift this time is just as jarring as it was the first time. Stiles' pale skin darkens and toughens into bark, oak branches erupting from his limbs and reaching up toward the sun. A massive bough stretches outward from his back, arcing up like a raised wing while flowers and grass and vines sprout from nowhere, hanging from the branches like decorative drapery and perfuming the air with a riot of floral scents. A cherry branch sprouts from the center of Stiles' chest, curling up over his shoulders to drape cozily around his neck.
Derek fights the urge to bare his belly and throat as Stiles' power pulses through the forest. Stiles is such a spaz most of the time that Derek always forgets how far above him Stiles is on the food chain of magical creatures.
Stiles opens his mouth and says something in his native language. It sounds like cracking branches and rustling leaves and is perfectly incomprehensible to Derek's ears, but Stiles makes a shoo-ing gesture, which Derek has no problems interpreting. He backs away, leaning up against a holly tree at the edge of the grove that's sprouting flowers so fast it's raining petals down like snowflakes.
Stiles says something to the forest. Derek can't understand it, but as part of Stiles' domain, he can feel it, a summons so powerful that he has to sit down to keep himself from walking over and presenting himself at Stiles' feet. A few seconds later, the buzzing begins.
The Emerald Ash Borers begin streaming into the grove from all directions, blocking out the sun like a cloud and landing on the dying ash trees until their trunks and boughs are a teeming mass of iridescent green. It's beautiful, in its own way and, though Derek would never admit it even under pain of torture, impressive as hell.
Stiles holds the beetles there through sheer force of his power as the last stragglers arrive, the scent of life growing so thick in the air that Derek covers his nose to block it out.
There's another pulse of power and the scent of life disappears entirely. Derek pulls his hand away from his nose to check and gets a whiff of something that makes him instinctively whine in distress. Then the corpses of thousands of dead Ash Borers are falling from the trees, their bodies forcefully stripped of the life energy that sustained them. A rain of shriveled leaves follows them down as the last of the life energy seeps out of the infected ash trees, leaving them just as dead as the insects that infected them in the first place. Derek grabs a fistful of Holly petals and presses them against his face, trying to drown out the acrid non-scent of death.
“What the hell did you do?” Derek gasps. He's trembling, and even though his instincts are all screaming for him to run away, his body feels like it's been frozen to the ground.
Stiles slowly shifts back to his more familiar human form, the flora and bark peeling away from his pale skin as he folds his power back into himself. He shrugs. “Like I said. I carved it out.”
Derek can't help flinching when Stiles takes a step toward him. His skin is itching with the competing urges to flee or to roll over and bare his throat to a superior being. Stiles stops dead, eyes wide, and hunkers down on the ground, surrounded by a carpet of dead borers and ash leaves. He watches Derek shiver, but looks away, clearly discomfited by Derek's obvious distress. The grove is dead silent for a few endless minutes, and then Stiles finally begins to explain.
“When my mom died,” he says quietly, sitting down and pulling his knees up to his chest, wrapping his arms around them, “my dad told everyone that she died of chestnut blight. She didn't, really. I mean, the blight is what made her sick in the first place, but it isn't what killed her.
“It wasn't that bad in the beginning. It was pretty much like she just had a cold all the time. But then it got worse because she refused to cut out the infection like she should have. But then, she was a chestnut spirit, like I'm an oak spirit, so it probably would have hurt a lot more for her to do it even though it would have saved her life.”
The scent of Stiles – of life – finally wafts over to Derek and he relaxes by degrees as it overtakes the scent of death. His hands and feet tingle as warmth floods back into them. “I thought you said she didn't die of the blight,” he forces out.
“She didn't. She died curing it. In the end, the infection spread through all the chestnut trees in the forest until it got to the heart of the forest where it infected the bower tree. After that, it was just a matter of time until it killed her, so she used all of her remaining power to make a cure. That's what really killed her.”
Derek forces himself to his feet, pins and needles tingling all over his body as he trudges through the detritus to Stiles. He breathes in his Stiles' scent, the smell of life chasing away the last vapors of ashy death. The cherry branch that grew out from Stiles' chest is still dangling from around his neck like a scarf, its blossoms releasing their comfortingly familiar scent and reminding Derek of the day that they spent growing their cherry tree. He reaches for Stiles, wanting to offer comfort, but falters midway, not sure what to do. Stiles gives a wan smile, catching and tangling Derek's fingers in his, and somehow it's enough.
“I mean, don't get me wrong,” Stiles continues. “It's great that she single-handedly saved the American Chestnut from extinction, but if she'd just cut out the infected trees in the first place, if she'd never given the blight a chance to spread, then she would still be here and my dad and I wouldn't've had to cut down her bower tree with our own hands.”
Stiles tugs on Derek's hand and Derek pulls him to his feet, catching him in a tight embrace. He leans his forehead against Stiles' and for a while they just breathe each other in.
Stiles uncurls the cherry branch from around his neck, snapping off one of the thinner twigs and dropping the rest with the oak branches he'd shed. With a little prodding, it grows into an oval, the two ends connecting seamlessly.
“What's that for?”
Stiles grins cheekily, the last of the shadows fading from his expression. “Well, when humans get married, they usually give each other a ring. So, here you go. A ring.” He sets it on Derek's head and the morning glory latches on to it, adjusting it lower and pulling it snug around the curve of Derek's skull.
“I'm pretty sure the ring is supposed to go on my finger. Not my head.” Derek reaches up to touch the branch and a cherry blossom opens under his fingers. “A crown. I can already imagine all the princess jokes my sister will make.”
“A coronet,” Stiles chides, smirking. “Because only the king gets to wear the crown and I'm so the boss of you.”
“I'll let you think that, if it makes you feel better.”
“Oh yeah? And who was half a second from baring his tummy when I pulled out the big guns?”
“That was just instinct,” Derek growls. “Can you grow a tree here?”
“Wow, could that transition have been any smoother? And no, not yet. I can help it along, but the soil needs some time to recover. Dare I ask why?”
“It's a surprise. Just tell me when it's ready.”
“Whaaaat? C'mon, tell me!”
Derek bites at Stiles' lips then catches Stile's chin between his teeth, growling. “No. Sto' askin'.”
Stiles laughs, the sound bright and healthy and happy, and Derek gnaws playfully on the ridge of his jaw, chasing the vibrations of Stiles' laughter with his tongue and making a mental note to get his hands on an American Chestnut seed.