/i
It feels like a forest fire burning through his skeleton and a phoenix in his gut. It feels like a sandcastle, standing majestic and impenetrable on the shore, before saltwater and a tidal wave reduces it to dust. It feels like a million sunsets and sunrises and dusks and dawns rolled into one, uncontrollable typhoon; there's stars being born and stars fading and the effervescent light of a full moon, but they're nothing. They're nothing compared to how much he feels and how much he hurts.
He's one hundred percent sure he's only got one heart, now. The other one left with her, as she tumbled to the ground, consumed in charcoal black. What's the use of dual thrumming when the only thing worth spending those heartbeats on is lifeless?
It hurts even more to know that it's all his fault. Like it always is. He gave her everything and everything corrupted her, warped her like clay in a kiln to this reckless and compulsive shadow of a girl; she wasn't Clara, by the end. He made her think everything could be fixed, that there was some miraculous equation that could reorder physics and cheat death and make everything okay. But there wasn't, and there isn't, and now he's left more broken than before she fell out the clouds.
He thinks of her smile, and her funny nose, and a pair of black leather boots that sit near the TARDIS door. He thinks of a laugh that sounds like butterflies in summer rain and chipped red nail polish and a tiny London flat. He thinks of three mirrors, 101 Places that she didn't get to see and how the memory is so painful it just sits in his chest, constantly, like he's breathing in sawdust and grit.
He thinks of the saltwater on his fingertips and how often he doesn't realise he's crying.
/ii.
There are a million wars he could wage and a billion stars he could burn but instead he returns to Akhaten – the first of the many worlds she saved. The markets are still bustling and for a moment he feels angry, how the universe is still turning and people are still shopping even though his whole world has just eclipsed into a grinding and devastating halt.
Then he realises; the universe doesn't stop because he's hurting.
No-one recognises him. The lines on his face are new to these people, the grey hair unnatural. Instead, he interweaves through the crowd like an echo, a whisper amongst the indefinable burr of voices and accents. The four eyes of a Groxx settle on him for an uneasy few seconds. His stare encourages him to bound away back to a market stall.
If it wasn't for her, you wouldn't be alive.
A hand reaches out for his shoulder. He starts, turning, ready to challenge. He's taken aback when a tall woman, swathed in crimson cloth with almost equally crimson hair, stares back at him. He knows that face. It's older, like his. It's seen too much, like his. The creatures at the stalls gawp and scarper. They know exactly who she is.
"Doctor," she says gently, her lips thin but refusing to smile.
He furrows his brows. "How did you…?"
"Oh, I knew," her voice is fluty, melodic, yet more rounded and sweet from when they last spoke. "I knew straight away."
Her hand reaches up to his face, the skin coarse beneath her fingertips. He flinches – the last time someone touched him there, where his chin meets his jaw, was…
Merry frowns. She can see a black hole in his pupils in the aftermath of a brilliant supernova, bursts of emerald and scarlet and dazzling gold all faded into black. She knows this because she felt it, too, right in the centre of her heart, the devastation threatening to rip open her ribcage. Because you know, don't you? You can feel when someone you could never forget vanishes into smoke, the person who saved you, even if it was only for half a second on the edge of a dream.
(He leaves not long after that and it's to a song that is so unbelievably sad yet so unbelievably hopeful. Clara Oswald is dead but her memory lives on. The universe will not allow her to be forgotten.)
/iii.
He takes it upon himself to visit Dave.
He wanders up to a house number that's scribbled in Clara's leather-bound address book, full of friends he's never met and faces she'll never see again. The door is blue, ironically, and the rocks in his throat make yet another untimely appearance. He presses the doorbell and immediately starts fumbling round for his prompt cards, page after page covered in Clara's neat script saying oh, you've had a haircut, it's lovely and you've certainly got a colourful sense in fashion! He would laugh if Dave wasn't standing in the doorframe.
He couldn't remember what Clara's dad looks like, but it all comes slotting back into his head like a jigsaw with a missing piece when he sees him. They have the same nose, the same bad taste in jumpers.
"Can I help you?" he says and god, it's the same accent too.
"Just a…" he's desperately searching for the right words, but there's no right, no kind, way of telling someone their whole world has just ended especially when his own whole world has just ended too.
The cards escape his hand in a paper waterfall, the brutal confetti of his loss, decorating the pavement like snow-white autumn leaves. He stands there in silence and Dave is confused, almost anxious. The Doctor slowly meets his eyes, and Dave can see the cataclysmic nature of his grief residing in the rippling blue of his irises.
And Dave knows. He just knows.
/iv.
(There's flowers outside Coal Hill School, flowers outside her flat, flowers outside Dave's house. Gold carnations, vermillion roses, lilies whiter than the light in the heart of the TARDIS.
He passes by the memorial outside her school. Children are crying, devastated, by the loss of yet another irreplaceable teacher. Courtney Woods catches his eye and he nods. She just smiles, placing a bouquet of peonies beside declarations of sympathy and love.
Because, hell, Clara Oswald was not short of people who loved her.)
/v.
There's the tiniest of cracks, barely visible, showing up on the TARDIS scanner. It's brimming with millions of possibilities like a desperate moth to a flickering flame. For a split second he considers it: pummelling through it, destroying everything, in the hope that there'll be a version of her on the other side. A version of her he will love and cherish and protect. He'd do it better this time. A parallel Clara in a parallel world.
Then again – no. Clara Oswald would not want him ripping apart universes to find her. Clara Oswald would not want blood on his hands in the hope he could save her one more time. Clara Oswald would not want him to find her only to lose her all over again, his hearts shattering for the hundredth time.
It comforts him, though, to think that through that crack, there's another Clara Oswald. There's an infinite amount of Clara Oswald's, living an infinite amount of lives, uncorrupted by him. She's still out there, living, breathing, even if it's not with him.
(Love is a promise. Pain is a gift.)