"Where've we landed, then?" Rose asked as she wandered into the console room and leaned casually against the Doctor's arm.

He didn't need to have a mental bond with her to sense that something was wrong. There were bags under her eyes and she shuffled her feet slightly against the floor grating as she walked - not skipping about with her usual excitement at the promise of a new adventure right outside the TARDIS doors.

"No idea," the Doctor answered, reaching out to run his hand down Rose's arm in silent question. Through the bond he could feel her haggard exhaustion as his own, but he couldn't quite pinpoint the source of her discomfort. The TARDIS made a groaning noise and Rose's thoughts wearily echoed the sentiment.

"I'm fine," she assured him with a weak smile as she met his questioning gaze. "Just ... tired, I think. Come on, let's see where she's landed us. It seemed a bit rough this time, is the TARDIS alright?"

The Doctor silently allowed Rose to dodge his curious concern, but he made sure to keep a tight mental hold on their bond all the same, wanting to make sure that if anything changed for the worse, he would know immediately. "Everything seems to be functioning normally," he muttered as he flashed the controls a curious glance and then moved to follow Rose out of the TARDIS doors. "I don't know what's wrong, though. She's sort of ... queasy. Indigestion, like she didn't want to land ..."

"Well," Rose replied with some measure of concern, "if you think there's going to be trouble, we could always get back inside and go somewhere else ..."

They both cracked at the exact same moment, their shared amusement ringing off of the walls in the cramped cupboard that they had landed in as they laughed out loud. However, it didn't take long for the Doctor to regret his casual dismissal of Rose's teasing words. It would have been so easy to heed the warning of the TARDIS in the back of his mind and the weary set of Rose's shoulders and insist that they fly away and land somewhere else - but once again, he had walked Rose by the hand and led her straight into danger.

Rose comforted him as best she could, but it was eighteenth century France all over again and the Doctor was forced to face off once more against his worst enemy yet (worse, even, than the daleks) - the dreaded slow path.

Rose teasingly joked about jobs and houses and mortgages, but the Doctor could see the image that she was paining inside of her mind and he knew that there was nothing insincere about the life that she was dreaming up for them. In her head, they lived a simple, happy life just like any other human couple back on Earth, filled with food and work and anniversaries year after year on a continuous, endless cycle.

The image didn't scare the Doctor as much as he thought it would - or, at least, it didn't scare him in the way that he had expected. It was still the slow path and so incredibly simple and linear, but the smiling, happy Doctor and Rose in Rose's fantasies made him think that maybe a normal life didn't necessarily have to be boring as well - not with her in it.

What scared him the most, though, was the way that Rose lingered longingly on the thought, combing carefully through the idea of a stationary, human life. The Doctor suddenly found that he was doubting himself for the first time since they had created their mental bond together. He knew in his bones that Rose loved traveling with him and wouldn't change their adventures for anything else in all of existence, but he suddenly began to wonder if perhaps they wanted two very different things.

Did she really dream about settling down and creating a life with him? Did she fantasize about a time at the end of their travels where they could simply live out the rest of their lives in domestic bliss? Was the Doctor even capable of giving those things to her if that was what she did want?

"I promised Jackie I'd always take you back home ..." he muttered wearily, not able to meet her eyes as her idle daydreams cleared from their bond and she returned to simply offering him small waves of comforting reassurances.

"Everyone leaves home in the end," Rose sighed offhandedly, staring down the black hole that was hanging above their heads as though she intended to personally challenge it.

"Not to end up stuck here."

"Yeah, but stuck with you, that's not so bad," Rose insisted quietly.

"Yeah?" the Doctor asked, tentatively reaching out over their bond to meet her reassuring touch and easing into the deep sense of satisfaction that he got from sinking into his bondmate's presence.

"Yes," Rose stated authoritatively, turning to smile knowingly at him as she let her mind fuse comfortably with his.

Her complete, assured confidence filled the space between them and overflowed into his mind, and the Doctor really had no choice but to believe her.

Still, he was the Doctor and she was Rose Tyler and they both had roles to play. As long as there were lives to save and people to rescue, they each had to do their part. So the Doctor volunteered to descend into the dark unknown without a second thought, and Rose let him go without any complaint or attempt to stop him.

Come back to me alive, she commanded through the bond long after they had said their goodbyes and the capsule was rattling along on its way down to Point Zero at the heart of the planet. She had a comm line linked directly to his environment suit helmet, but this demand she transmitted silently straight into his thoughts - a message just for him.

The Doctor closed his eyes and focused on the bright light of her consciousness as it slowly dimmed and faded from his mind. With every mile that was put between them, he could feel his grasp on Rose's mind unraveling as the bond thinned and slipped through his fingers. He tried very hard to keep his panic hidden from her as his breath became shallow and his thoughts began to race. They hadn't even been bonded for very long, but he was already losing his grip on her mind for the second time since he had come to fully embrace her presence in his head, and he was beginning to wonder if it would ever get any easier to let her go, or if it was always going to be this unbearably painful.

Stay safe, he finally replied, giving his own last, desperate command. I'm coming back for you.