Unavoidable
Donna watched the Doctor as he bounded round the Tardis console excitedly. He was going to take her to a planet called Midnight where she could finally have the peace and rest she deserved after all the running they'd been doing.
She couldn't wait to get there but she still had to wait while the Doctor did his usual tinkering. They wouldn't be going anywhere until he finished and to be truthful, Donna wasn't that fussed. As long as he didn't side track by landing them on the wrong planet she was happy.
And if he did… well, Donna's hand was always ready to give him a nice hard slap.
Sitting on the Captain's seat, she closed her eyes and found herself dozing off as the Tardis' gentle hum lulled her to sleep. She found herself thinking about the day she first met the Doctor. Her wedding day. She'd been walking down the aisle with her dad until golden dust surrounded her (she'd later find out that they were huon particles fed to her by her so called fiancé) and had been transferred to the Tardis.
She remembered how terrified she's been especially after seeing the stick of a man standing near the console. She'd used the anger she felt to drive away her fears. After that it was all a blur. Robot Santas, killer Christmas trees, jumping from taxi's, sitting on a roof, getting a ring, giant spiders, realising her fiancé was a spider loving freak and then…
She opened her eyes and looked at the Doctor. He stood there, concentrating as he fiddled with some kind of contraption. She remembered how he'd stood there drowning the Racnoss, not showing any mercy at all. At that moment she'd felt more terrified off him than she'd ever done before but now she knew why he'd done it.
Rose.
The one person in the whole of the universe who could possibly make the Doctor happy was stuck in a parallel universe with no way to get back to him. She knew it was impossible for them to get back together. The Doctor had said that if Rose found some way to come back, the universe would collapse.
It was quiet tragic really.
And though Donna always put on a front that she didn't really care about the Doctor that much, she did. A lot. More than she should, really. It wasn't that she was in love with him the way Rose and Martha had been. Her love for him was completely platonic, she knew that.
But she still cared about him so much and just wanted to see him happy. And the only person who had come close to making him happy had been killed by a war driven psycho.
Jenny had been in the Doctor's life for such a small amount of time and yet she'd made him so happy. And then even she was taken so cruelly away from him. It was always the Doctor who kept losing people who meant so much to him. Whether he wanted to or not.
He was such a good man/alien and yet he didn't seem to be able to find any happiness in the world. And if he did, it was always taken away from him. How could someone so good be so unlucky? Sometimes she thought that he just couldn't avoid loosing someone dear to him just the same way as he couldn't avoid getting into trouble.
She remembered how he'd dropped her home, asked her to come with him and how she'd turned him down. At that time, she'd been too scared of him. All she'd wanted to do was travel the world and have a normal life.
It was only after her dad died that she'd realised just how much she needed to find the Doctor again and get away from her normal life. Because normal just wasn't her. She needed to get away from her mum who wouldn't stop nagging her about never getting a job. She wanted excitement and adventure. Two things the Doctor could definitely give her.
She remembered how happy she'd been when she'd found him, how sad she'd been when she thought he didn't want her to come with him, how shocked and annoyed she'd felt when she'd misunderstood him about the whole 'mate' thing and how happy she'd been when he said that she could come with him.
The wanting to be a mate scene replayed in her mind. She'd never really wanted the Doctor in any way apart from as a friend. She'd never dream of ever falling in love with him and for him to reciprocate her feelings.
For one thing, he was just a stick like man with crazy hair, who had a weird craving for bananas and licking things. Totally not her type, at all. Especially as she was a human and he was an alien.
And he was completely and deeply in love with his Rose.
Poor Martha. She'd fallen for him but he'd never felt the same. At least now Martha had moved on and was happily living with her fiancé. She wondered if the Doctor would ever get his Rose back. She knew it was impossible but at the same time, she didn't think having a little hope would be too bad.
Because if Rose came back, then she knew that the Doctor would be the happiest man in the whole of the universe. And that's what she wanted him to be. Happy. Because even though she didn't love him as more than a friend, she still loved him enough.
As Donna let her thoughts flit through her mind, she realised that just as the Doctor couldn't avoid losing someone or getting into trouble, in the same way anyone who met him couldn't avoid falling in love with him. Platonic or not. It was completely unavoidable.
And with that thought in mind Donna walked over towards the Doctor who'd finally finished and announced that they could go to the planet Midnight. He pushed some buttons and pulled some levers and did the regular hitting the console with the hammer before the Tardis landed with a gentle thud. They walked to the doors and the Doctor looked out.
It was the right planet for once and grinning he took her hand and pulled her out telling her all about the wonders of this planet. In that moment, Donna Noble decided that she was going to travel with this man/alien. Forever. And possibly help him find his Rose. So that they could all be together. Forever.