On Gallifrey there was an Academy. It excelled in all of its studies and it's student went on to get great steady jobs on the cities across the planet. Parents of grand houses fought for a way to get their kids into the academy. This was because the academy was very good of taming wild Gallifreyan children. Those kinds of kids who never did what they were told and could one day become criminals or worse renegades of society. Children who are far too clever to listen to the rules and by the judgement of their elders doomed to become outcasts from Gallifrey . Destined to cause mischief across the galaxies.
Families with status feared the damage one renegade relative could cause to generations of their great ancestors, so it was only right to have the wildness drummed out of them. For their children to settle in good safe careers in middle management, which would never give them any dangerous or exciting ideas. It was, after all, for their own good. The parents thought their children would thank them when they were old enough to understand responsibility (about 750 years old or so).

The new Professor of Sciences at the Academy hated the school. She was forbidden to teach a complete course of Time and Space studies to her students and to keep ideas out of their heads. This was ludicrous to her as these children were future time lords after all.

When some of the students discovered her last job was at the Grand Time Labs where such inventions like the first TARDIS was constructed, they badgered her all day about time travel and how the technology worked. Not wanting to lose her new job too, the Professor made it very clear the academy had made such studies forbidden. In fact she had to put all of her books on such dangerous subjects under lock and key in the schools science labs. She would also make sure to walk as loudly and slowly as she could back to the classroom after lunch and ignore the sound of school sonic screwdrivers unlocking doors and pitter patter of tiny feet running from their first mini rebellion.

It wasn't enough for the Professor. She had another row with the Headmaster about organizing a small school trip into another galaxy or even fundraising for a school TARDIS, which they could use to reward trips with for good behavior. She argued hard about how some of the students despite showing signs of being renegade, also showed great promise. For example how one student (whom she couldn't recall the name of) stole her sonic screwdriver so he could disable a weapon used by a bully at the school. For the Professor it showed that breaking the rules could have positive outcomes and that having exciting ideas shouldn't always mean disaster. Unfortunately she was denied the request again. The Headmaster was snide in reminding her of the demotion from the great labs and that she was not destined to be a great architect of time but instead become content in teaching the rules of safety in science. According to the smug Headmaster the Professor was lucky to have been given a second chance by the academy. It almost like she was being re-enrolled to learn her place on Gallifrey all over again.

To the Headmaster it looked like the Professor went on to follow the rules and teach the students how society deemed they should be taught. On the inside there were big bad rebellious ideas brewing.

During the holidays the Professor had snuck into the Great Time Architect labs and was stealing parts from old TARDI. Back at her home lab she started to construct her own TARDIS for her students. Yet, in her rush she made a miscalculation causing the heart of the TARDIS to grow volatile and explode. The safety mechanism was triggered and the professor was stuck in a time lock. Her computer reported she was safe bubbled inside time where she could live out all of his hearts while the moment outside stayed still. However, when she died or turned off the shield the explosion outside would kill her instantly as it raged within the blast and time proof walls of her lab. The explosion of time was enough to burn all of the Professors regeneration's the computer said and it would be best to write her Will and make peace if she so wished.

The computer beeped again. It reported her lab would contain the blast of time, which caused more problems. The explosion of volatile and self sustaining itself and as it was not able to fully burn up and would continually grow until there was enough energy to burst the laboratory walls and destroy the entire city and its population.

After kicking herself over the rash mistake the Professor had an idea. With all of her lives and the enough equipment she could do the one thing she wanted to do in her entire life. Become a great architect like her ancient elders and invent a device which could cage the explosive time. She got to work spending centuries studying and tinkering.

After much studying and calculations she had completed the device. It looked like a small box with complicated ancient Gallifreyan scribed layers of moving parts getting smaller and smaller as they revolved inwards. It was quite simple, the box that would absorb the explosion of time and become powered by its energy. The device was smart, it would make sure the explosion would never escape and use its own power to help keep it in prison as long as the device was never switched off. The explosion could become big enough to destroy the universe but the box would always be one step ahead at containing it. She needed to get the device working first and that would only happen at the moment the volatile time was almost powerful enough to burst her labs blast walls. For the Professor it would mean death, but for her city and her students it would mean life. When the Professor shut down the generators powering the two time locks the box did its job, the moment of volatile time was sealed.

Not long after her old work colleagues entered her lab they found a large spike in time was registered inside the device. They took The Moment safely away reading the Professor's clear worded instructions not to turn it off. It was seen as a weapon and locked away in the Omega Arsenal where they pretended to the council it was an ancient weapon (in case anyone in middle management got any ideas of inventing more devices). Later on her personal possessions were packed away, some of her books were donated in a Will to her students and in particular one student was given a letter saying he could keep the sonic screwdriver they had once cleverly stolen but only if they promised to use it for the good of the universe.