She knew that everything he was saying was true. In her heart, she yearned to see everything he had to offer. New planets, times far in the future or long forgotten, beautiful, dazzling sights that most humans would never get to see. She could almost picture it: The Doctor and Robin, characters written about in legend or folklore, hurtling through the stars together and making sense of each other.<br/><br/>She wanted it so badly. It scared her.<br/><br/>At his mention of sidekicks, she barked a laugh. Of course he'd had to change Batman and Robin, but she felt she could get one more jab at him.<br/><br/>"Yeah, obviously, you'd always be the shining hero, so... That makes me the bumbling sidekick, silly and stupid and always getting into trouble." Her sadness seeped into her smile despite her best efforts this time.<br/><br/>"I do want it, Doctor," she whispered, hugging her arms around her body tightly as if trying to hold herself together, "I want to travel with you, and help you, and see things... But I'm too scared. I'm getting this horrible feeling, like I'm almost sick or something. I can't pull myself between the worlds, but I can't completely separate myself from this one. I have a normal life!" At this, her voice had risen to almost a shout, though she still could not bring herself to look at the Doctor.<br/><br/>"You... All of this... You're terrifying! And you're spectacular! And I'll never be able to get it out of my head. But that will have to be enough, because I just can't come with you, Doctor. I can't. It's too much for me."