The night Jacob Black phases for the first time, he is lying in Bella Swan's arms. It is not the way he has repeatedly fantasized about it. His skin feels like it is bubbling under the surface, and Bella claims that he's burning up, but he feels cold as ice and itchy – so itchy he could rip his skin off and start again. He could swear – it sounds so strange – that his very bones are moving of their own accord under his skin. And he's got to be hallucinating, because even as Bella is leaning over him on the couch saying "Jake, Jake! Stay with me Jake or I swear to god I'll kill you" – even then he can smell every particle of her skin almost like he can taste her and he's filled with both longing and fear.

He thinks he's probably dying.

Bella, for one, can't believe what's happening. An hour ago she was with Mike Newton and Jake at the movies– Mike went home sick, and Jake seemed to crumple and collapse beside her. She didn't let him go for a second. Somehow she managed to half-drag, half-support him to the car. Hospital, she thought. Right now. She drove with shaking hands, all the time giving anxious glances at Jake's unnaturally ashen face in the passenger seat, as he leaned forward, his curtain of hair hiding his eyes. It was terrible seeing him felled like this. Just. Not Jake. She'd phoned Billy on the way to meet them at the hospital, but when he asked what Jake's symptoms were and she told him, the line went curiously silent for the longest time.

"Billy? Are you still there?"

"Bring him home, Bella. It sounds like mono."

"You are kidding, right, Billy?"

Bella could be pretty stubborn, that was no secret. When Billy wheeled out to the car, she ignored his pleas to leave. What did she care if she caught this virus, whatever it was? This was Jake, and he was in pain. End of.

"What you going to do Billy, put him on your knee and wheel him inside?"

"Sam will be here soon."

Billy kept saying this, like a mantra. All the time Jacob was lying on the sofa, avoiding eye contact, somehow inside himself. Billy was twitchy as a grandma stealing from the offerings plate in church. Sam will be here soon.

'So what?' Bella thought. 'I'm staying.' It wasn't like Sam Uley was known for his medical skills. Maybe this was some Quileute thing, that they thought they could heal him with – what – herbs? Prayer? Dancing in the moonlight? Okay, maybe not that.

Now she keeps going to Jake, holding him as he lies on the sofa, stroking his forehead, pulling his hair back off his face. Billy tries to shoo her back – "Bella, it's not safe. Please. Stand back from him a little."

His eyes. Oh God. They are black with pain. And then his whole body begins to convulse. Bella does step back then, more out of fright than anything, and feels Billy grab hold of her.

Jake is screaming. No. Howling. And there is a noise like something wet being torn – a blur, a rush of wind at Bella's side as she is flung to the floor, dazed.

"Get OUT Bella!" Billy's voice rises in panic. The room is spinning.

Bella's eyes seek Jake. He is not on the sofa. He has gone. She briefly takes in the remains of his black T-shirt and denim jeans shredded on the floor.

In the far corner of the room there is a gigantic hairy animal growling and snarling.

"It's okay, Jacob," says a soothing voice from the doorway. Bella and Billy have backed away, are pressed up against the opposite wall.

"Sam," Billy urges.

Bella cannot speak. She watches the tanned figure of Sam Uley – wearing no shirt – walk across the room holding up one hand. He shimmers, then bursts – no other way to explain it – and suddenly Sam is gone and there are two wolves in the room.

Bella's mind struggles to compute.

She stares silently as the black Sam wolf crosses the room, and nuzzles the form of the reddish haired wolf who is still huddled in the corner. The moonlight suddenly breaks through the window and lights up the room. Bella can see the outlines of trees; Jake's garage where they'd spent so many days fixing cars. Is it possible that world is still there? It seems in an instant everything has changed.

"Jake?" Bella moves with trepidation across the room. The black wolf growls at her, but she keeps going, stopping a few paces away from the reddish furred wolf and kneeling down on the floor.

She looks into his eyes and sees fear. And something else.

"Jake, are you there?"

She reaches across and strokes the back of the wolf. He looks so afraid.

"It's okay, Jake. Whatever this is, I'm here."

The wolf whines. The black Sam wolf has backed away, his tongue hanging out, watching, calculating.

"I'm sorry Sam. She wasn't meant to be here if this happened," Billy explains.

"You knew about this? You knew this could happen? And you didn't tell him?"

Bella starts to cry.

Okay, so I'm a wolf, Jacob thinks. And a hundred synapses in his brain explode. He has images assault his memory: every strange look Sam Uley has given him lately; all the times Billy asked him if he was feeling hot; the way that smells seemed to be almost physical objects lately; the itching.

Okay, so Sam Uley is a wolf too. And somehow he's inside his mind having a cosy little chat that runs along the lines of this is your Quileute heritage blah blah blah…spirit wolves who can transform between human and animal form blah blah blah…really amazing once you get used to it…

Is this guy serious?

And then everything is okay, because Bella is there, and she's touching him, touching his fur, of all things, and he starts to calm down. Because even if he is a wolf, at least she is there. She has not run away screaming, like she should. Why has she not run away screaming?

Jake looks into her eyes, and feels the universe expand. He sees stars collide and meteors implode, and entire solar systems flash past his consciousness. His heart reaches out from his furry chest and latches onto Bella Swan. She. Is. His.

Bella curls up beside him and holds him around the neck, murmuring to him, and his breath slows till he begins to quiver a little.

"Bella, let him change back now," Sam Uley, in human form, gently pulls her away from Jacob. The wolf shimmers, contracts, and Jacob is back. Sam is gripping her by the shoulders, leading her away from him through the doorway.

"Come on, Bella, give the guy some privacy. He won't want you to see him like this."

"Oh…" Bella looks back. Jacob is very naked – strong, curled around himself, like a warm living Greek God. His face is a real picture. Bashful. Joyful. Confused.

This is the night that Jacob imprints on Bella.

From here on in he doesn't want to let her out of his sight.