To find a pair of sisters more devoted to one another, you would have to look very hard. Bella and Alice Brandon-Swan were twins, 16 years old, and pretty much inseparable. Looking for one, you would always know the other was nearby. Both were popular at their school, Forks High, each happily in love with a kind boy, in Alice's case it was Jasper, and Bella's boyfriend was Edward.

The sisters talked about everything and anything to one another, frequently freaking people out by finishing each other sentences. There were no secrets between them, not ever. So when Alice started feeling slightly under the weather, Bella was the first to know. Alice was constantly tired, she couldn't concentrate on her school work and she just generally wasn't her usual self.

Neither of the girls were at all overweight, in fact they were on the more slender side of healthy, but soon Alice was losing weight, looking gaunt and haggard. Odd bruises appeared on her arms and legs, for no apparent reason. After three weeks of this, Jasper finally drove his girlfriend to the local A and E department.

Then the bad news came. It turned out that Alice had acute lymphoblastic leukaemia, or ALL. It explained all the symptoms. Aside from Jasper, Bella was the first to know. A mixture of relief and anxiety rushed over her. Relief that at least they knew what was wrong with her sister and anxiety because no-one knew what the future could hold for her.

Alice was immediately put on a course of chemotherapy, which made her ridiculously sick, but it seemed to be helping her ALL. When her hair fell out, nothing could stop the tears that fell from her eyes. Alice was always so fashion conscious; she loved trying out new hair-styles. Even though her hair was fairly short, it was still a shock to see the tufts of black lying in front of her.

Bella stayed with her sister 24/7, only leaving her side to get her some food, drink or to go to the loo. She slept on a put-up bed in Alice's room, at her side in a flash if she even coughed. Bella felt so guilty that it was happening to her sister, they were twins, shouldn't it happen to both of them surely?

Every time Alice made some small slight achievement, like managing to walk down the stairs by herself, tears filled Bella's eyes, and the smile on her face was almost indelible. But despite trying to stay strong for Alice, the façade faded as she lay in bed carefully listening to the sound of Alice's shallow breathing.

Not even Edward could separate Bella from her twin, despite the fact that Alice needed hardly any help any more, Bella stubbornly stayed with her 'just in case'. She couldn't bear the thought of losing her sister; it would be like tearing herself in two.

After Alice had endured six months of chemotherapy, her doctor suggested that a bone marrow transplant would be a good idea, potentially meaning that Alice could be in remission a lot sooner. Naturally Bella was the first to volunteer to be the donor, and after some test to make sure there was a little possibility of rejection as possible, the date for the operation was set for the twins' 17th birthday.

The procedure was explained to each of them, both having to take special medication to assure success. The night before, Bella crept into her sister's side room on the ward and got into the bed with her. Alice woke with a start, but smiled when she saw her sister. Her black hair was growing back, slightly fuzzy, but at least it was a start. Bella felt like she was finally doing something really useful for Alice. It had been hard not being allowed to see her for the whole day.

'You scared Ali?'

'No, not really. I'm scared for you though. You know, you don't have to do this, you can still back out, I wouldn't hold it against you.'

Bella didn't reply, she knew exactly what she was doing. She just budged up in the bed and moved Alice's head onto her chest, and stroked her hair until they both fell asleep.

They woke to a start, a nurse bursting in frantically looking for Bella, she was due to go down to theatre soon, and had to take her pre-meds.

'Happy birthday Ali, I love you! I'll see you later, and then I'll give you your present.' Bella smiled as she was wheeled back to her ward. A tear rolled down Alice's cheek as she waved to her sister. She just sat and waited until she was called down, her mind never far from her sister.

Her mum fretted over Alice, it was tough for her to have both her daughters in surgery on the same day. Bella was first giving the bone marrow by transplant, like giving blood, and then having the operation where they would take the bone marrow direct from Bella's thigh bone. That was the fairly risky part of the whole procedure.

No-one would give Alice any information about her sister, so she got more agitated. She had to know what was going on, she was really scared for Bella. 3 hours of fretting until she was taken down to theatre. When she got down there, she saw Bella smiling, lying on a bed similar to Alice's. Alice breathed a sigh of relief when she saw here. The sisters smiled at each other, and then were given the anaesthetic.

When Alice woke up in the recovery room, she was surprised not to see her sister. She was desperate to know Bella's condition. When the nurse came in to check on her, she asked about Bella. The nurse's face fell slightly, and she went to get the doctor.

That's when Alice's world fell apart. The surgeon told her that Bella had been fine until they started closing her up. Her heart started beating erratically, until it stopped. She had been defibrillated over and over, until the decision had been made. She died.

Alice had still been given her sister's bone marrow, and she was doing really well. But Bella had died to save her sister. Alice was angry at herself, angry at the surgeon, angry at Bella. She didn't want to carry on without her sister. They were two halves of the same whole. Edward ran into Alice's room, tears running down his face. Jasper came in behind him, a single tear rolling down his cheek. Arms wrapped round Alice, arms that gave her strength. She was determined to beat her ALL, she was doing it for Bella.