She had fond memories of her travels with Ian and Barbara; okay, the Doctor now freely admitted she had panicked and made a fatal and rather stupid mistake by snatching them out of their timezone, but they'd taken her and Susan by surprise and the Doctor had reacted out of instinct. By the time she had realised her mistake, they travelled lost in time and space until they'd left in the Dalek time travel capsule that chased them across the universe.

She missed those days. Not only was she travelling through the universe and doing what she'd wanted to do since being bored to tears by her time at the Academy, but she was seeing worlds she had only heard in passing in her years on Gallifrey.

She had seen the primitive cavemen of Earth.

She had witnessed the crusades.

She'd met Marco Polo.

But she'd also visited the French Revolution, and that was one of the reasons why the Doctor was back in France. The TARDIS had picked something worrying up, and the moment she arrived, the Doctor idly found something familiar about the place. It was similar to what she would have felt had she landed in Totter's Lane, the Petrified Forest on Skaro, or on Maitland's Ship, or the bank of the Thames in the final days of the Dalek's invasion of Earth in the 22nd century, and she realised she had been in that exact spot before. Once she had explored the place and realised the effects branched out from the exact spot the TARDIS had landed in, the Doctor returned and ran a check with a sinking feeling in both of her hearts.

The TARDIS had created the problem.

At first, the Doctor was confused; ordinarily, when a TARDIS materialised, it created a wormhole from the vortex and into the landing spot, but the damage was always fixed. But on this occasion, it hadn't happened. Her TARDIS had always been very badly damaged, and it was one of the reasons she was able to take the old girl away from Gallifrey when she'd made the decision to leave with Susan. And thanks to the risk of being found by the Time Lords in case they'd stayed for too long, the Doctor had never had the time to properly do some work on the old girl; over the years, it was simply pushed out of her mind.

But the damage had been considerable, and after the nightmare, they'd had in just landing in 1963, the Doctor and Susan had decided to do some work on the TARDIS so it wouldn't stall or break down so thoroughly that the old girl wouldn't work again. They'd done quite a bit of work, but the TARDIS still suffered from so many problems, and because of Ian and Barbara's unexpected interference because Susan had been too stupid to not keep her mouth shut and had raised too many red flags for them not to notice, they had left 1963, and the problems had still followed.

The Fast Return switch was shot; it had fused completely on the second attempt when the Doctor had tried to get them back to Earth and they'd ended up on Skaro, but the Doctor wasn't sure if being thrown so far back into the past to around the beginning of the universe was worse!

The chameleon circuit had totally failed, and the TARDIS froze in the shape of a police box.

The navigational circuits were fried, the dematerialisation circuit wasn't working properly, and the dimensional stabilisers still froze in the sixth damn power!

But as she examined the situation here in France, the Doctor realised with increasing horror that because of her careless disregard for the TARDIS's problems, preferring to ignore them so then she could go on her random package holiday deal through the universe, the TARDIS….had been leaving fractured space/time trails in her wake!

Some of the damage was fairly localised, especially since there were some planets the Doctor's TARDIS hadn't landed on except once or twice, but Earth was an exception. How many times had she landed on Earth, especially when she had been travelling with Ian and Barbara? How many times had she landed in the 1960s? She had after all accidentally programmed the faulty navigational controls to land in the 20th century, and she'd only discovered that in her previous incarnation, although she just found it so odd that it would happen after Ian and Barbara had left. She must have landed in the late 60s more than she'd expected. But there was no telling how much damage she had done. From what the Doctor could tell, the TARDIS had been too badly damaged to fully seal up the wormhole she'd used to materialise and then dematerialise, so there were small cracks in time that were invisible to all but the most advanced scanners, and this one…

The Doctor had asked around and discovered most people avoided walking in the area where the TARDIS had landed during her trip to Revolutionary France, because they would always hear the voices of people screaming and struggling in the revolution, to say nothing of the later years of history. Moments of the future were bleeding through into the past, and so was the future. And it was all her fault.

What she couldn't grasp was why the Time Lords hadn't discovered this was happening.

Okay, usually they would ignore problems and changes to the timelines - they couldn't fix everything - but they usually monitored effects on history that could have devastating consequences. The Doctor wasn't sure if her travelling had caused more harm over the centuries, but if this was just a symptom of what could happen from one visit, she didn't know if there was anything worse from more visits. It could be little things, like a postman delivering an important letter to the wrong address, or rain falling slowly to the ground, but it was happening.

The Doctor knew that the TARDIS was currently not in the best condition to fully repair this damage; but now, this was going to be a major project for her to cope with. She wasn't going to ignore this, but right now there was little she could actually do. Sadly she set the TARDIS to leave, promising to return and fix the mess she'd caused.

Why hadn't the Time Lords discovered what was happening?

Author's Notes - This one-shot was inspired by a page on the Doctor Who wiki where the Accord tried shoring up Earth's timeline due to damage caused by the Doctor's TARDIS. I felt it would be a great idea for the Doctor to explore that possibility.