It's nearly midnight when Thunder, Lightning, and Cloud reach Ponyville. The kitchen lights are on in the house. Thunderlane sees the silhouette of Redheart pacing in the kitchen. "Looks like we're in trouble," says Thunderlane.
"Psh, what's the intern gonna do?" asks Lightning.
They land on the porch and enter the household. Redheart scurries into the living room at the first sign of their arrival. "Where have you two been?! You're mother was so worried. You have no idea how I felt watching her cry."
"Yeah, we do intern," Lightning Dust says icily. She walks past her to go to her room. Redheart's face softens, realizing they have much more to worry about than she does.
Cloudchaser taps Thunderlane on the shoulder. "I'm going home. My mom must be worried about me too."
"Okay, stay safe."
Cloudchaser smiles at Thunderlane. She hesitates for a while, fumbling her hooves around. She opens her mouth to say something to Thunderlane. Instead, she just sighs and walks out the door.
"She forgot her basket." Redheart points at it.
Thunderlane leans forward as if he is going to go stop Cloudchaser. "Ah, I'll give it to her tomorrow."
Redheart rolls her eyes. "No, you're not. You and your sister are going to stay here where I can see you."
"Fine," says Thunderlane.
Thunder is about to head to his room when Redheart stops him. "Hey, there's something I need to tell you."
"What is it?"
"Your mother is getting worse"--Thunderlane's heart freezes--"faster than we originally diagnosed. I fear she only has a few days left to live. If you need anypony to talk to, you know I'm here to help."
Thunderlane looks at his hooves. He can feel them trembling--pulsating with uncertainty about the future. "Thanks for telling me, intern." He walks away, figuratively stomping on her offer to help.
Thunderlane enters his moonlit room. "Hey, Lightning Dust--"
Lightning Dust is on the top bunk bed with her back facing him. "I heard..."
Thunderlane gets in bed to try and forget this mess life placed on him and his family. Tearfully, he nods off into a dreamless slumber.
A deep boom startles Thunderlane awake. Rain pelting the outside of his home sounds like rocks. Thunderlane hops out of bed and hurries to the window. No matter how terrible his life gets, the rain always perks him up when Cloudchaser isn't around. It soothes him.
Drops of rain crash against the glass panes of the window. The dark storm clouds above speed violently across the sky. The wind flies in every direction dragging along the rain and clouds. Thunderlane's face is planted flat against the window. He's absorbing every detail of the storm.
He steps back and flies up to Lightning Dust's bed. "Lightning, wake up. You gotta see--" He lifts the bed sheets. Lightning Dust isn't under them. "No, she didn't." Thunderlane stares back outside at the growing tempest. "Lightning," he whispers to himself.
Thunderlane gallops to the living room. On the couch, Redheart sleeping. He checks the front door which should be locked. He wiggles the door knob and the door swings open, letting in a piece of the storm. He slams the door shut before Redheart wakes up. She stirs, but remains asleep. Thunderlane puffs up his chest. He reopens the door and steps outside, quickly closing the door behind him.
Rain drops practically bury themselves into Thunder's flesh. A sudden flash of light dazzles him while the resulting boom numb up his ears. The wind tugs at his wings, pulling out some loose feathers. Thunderlane covers his eyes in order to see in this chaos. He places one hoof forward, anchoring it as hard as he can to the ground, and walks onward into the storm.
"Lightning Dust!" Thunderlane screams out, but the gale smothers his voice rendering it to a whisper by comparison. Another bolt of lightning makes itself known. This one strikes close to Thunderlane causing him to jump. It sets the grass around the strike on fire, but the unrelenting rain quickly overwhelms the helpless flame. The subsequent thunder hits Thunderlane as if it is physically solid. It knocks him over. The very ground shakes in fear. Thunderlane struggles to his hooves.
"Lightning Dust!" he calls out once more. A flash of light reveals a fleeting shadow in the clouds. He squints against the wind to make sure it wasn't a trick of the eye. The wind moves some of the clouds in the way. Behind them flies Lightning Dust trying to fight the storm. Thunderlane opens his wings halfway to chase after his sister when the gale grabs hold of them, jerking them painfully behind Thunderlane like a flag caught in a hurricane. He screams in agony. He desperately tries to fold them back in, fearing they're going to be pulled right off of his back, but the wind's grip holds them in place.
He can't take the pain anymore, so he jumps up allowing his body to be at the mercy of the storm. The storm tosses him back, sending him rolling across the grassy field. He hits a tree back first. His wings pulse painfully pinned against the bark of the tree. Thunderlane winces at his aching wings. He scans the sky for Lightning Dust from behind a veil of tears.
A series of flashes cross the sky, but one of them proves to be fatal. A bolt hits Lightning Dust, knocking her out of the sky. The storm treats her like a rag doll. She plummets, tossing and turning on command of the wind. Thunderlane's jaw drops. "No, I can't lose you too."
A voice comes from out of nowhere. "Catch her."
Thunderlane scowls at the storm. "You will not take away my sister!" Thunderlane kicks off the tree and leaps into the air. The wind grabs his wings again. He pushes it aside by swaying side-to-side like his dad taught him when facing a strong head wind. The very wind holding him back is now helping him save his sister. Lightning's body is falling too fast though. There's no possible way Thunder can reach her before she hits the ground. Not at this rate.
The same voice as before reaches out to Thunderlane. "You can do it. I believe in you."
Thunderlane realizes who is talking to him. "So you are watching." Thunder smiles. With a new found energy, he strives forward. "I will catch you. I will save you. A bolt of lightning hurt you. This storm hurt you. I will face any storm to save you." Thunderlane repeats that over and over. Something tingles on his flank, but Thunder dispels it from his mind. He clears his mind of every thought save for catching his sister. The strain from the wind dissipates from his wings, the rain water avoids his presence, and bolts of lightning strike down all around him but never actually touch him. The roar of thunder from the lightning rides next to him. He speeds along with it.
Lightning Dust's limp body gets closer. Thunderlane reaches out for her with his two forelegs. She falls directly into his hooves. Clutching her close, he folds in his wings and falls. Thunderlane positions himself in a way so his body will receive the full force of the impact. They skid across the grassy field for a half mile before slowing down to a stop. Thunderlane holds on to his sister. His afraid that if he lets her go, she'll vanish.
He feels her body tremble under his embrace. Thunderlane begins to laugh. His laughter grows more and more intense. Finally unable to laugh any longer, he ends it with a sigh and smiles. "She's alive."
Thunderlane carefully stands to his hooves. Lightning Dust cracks open her eyes. Her hair standing on end bounces around as she coughs. She sees Thunderlane watching her re-cooperate from her near-death encounter. Her eyes flick to his flank. She smiles and passes out soon after.
Thunderlane follows where she looked at. On his flank is the mark of a storm cloud with a single lightning bolt coming out of it. His mark, his talent, to face storms to protect the ponies he loves.