As the Doctor entered his TARDIS and set it to take him anywhere, his thoughts turned to Jo.

No, he would not be forgetting Jo Grant anytime soon, especially since she was the one who was responsible for the cat infestation that he'd yet to completely eradicate...

It had all started innocently enough. A number of feral cats had decided to make UNIT property their home, and Jo Grant had caught the troops dealing with the problem. Upon learning that the cats in the traps were going to be taken to the pound where they'd likely be euthanized, Jo had begged the men to let her have the poor creatures.

Jo almost immediately learned that taking care of five feral cats was a nearly impossible task, seeing as they did not appreciate human companionship, and demonstrated this by bringing the claws out and backing up to the far end of their cages when she tried releasing them from them the instant she got home. Deciding that it would be far better to turn the creatures loose into the wild where they would be happier, she started trying to think of a place where they could be free without running the risk of being captured again and taken to the pound, or run over by a car, or eaten by foxes, or a million other things that could happen to the poor felines. Remembering the rather nice garden aboard the TARDIS that the Doctor had shown her only the week before, a garden which the cats were sure to like, she came up with a plan.

The next day, she snuck aboard with the first of the cages and made her way into the back unnoticed while the Doctor was busy fiddling with something on the console. After making four more trips past the preoccupied Doctor to the garden where she had been forced to shake the frightened felines out of their cages, her task was done. As Jo departed leaving the cats behind in a garden which was located at the end of about a half mile of seldom traveled corridor, the TARDIS which had been programmed to not let any of its inhabitants starve after that one incident quietly relocated a food dispenser and started rationing out protein pellets for the Doctor's surprise gift.

The Doctor probably would've found the cats and swiftly dealt with them if it hadn't been for the distraction that had been caused by that Omega incident and the lifting of his banishment. In his excitement over being allowed to travel, he had set off on a solo trip which had lasted a couple of decades. A couple of decades during which the TARDIS's cleaning units and waste disposal units which took care of the miles and miles of rooms and corridors that made up its interior quietly dealt with the cat urine, feces, and hair problem, the TARDIS's food dispensers quietly issued increasing amounts of rations, and a number of small four-legged predators multiplied in the shadows keeping well away from the strange creature that shared their domain.

Anyone who has seen one of those charts that illustrate exactly why you should spay and neuter your pets would know exactly what happened while The Doctor was traveling around the universe visiting alien worlds. By the time the TARDIS returned to Earth and the Doctor had resumed his friendships with the people from UNIT whom he'd discovered that he'd rather missed while he was away as if he hadn't been gone at all, there were at least a thousand cats aboard.

Due to the fact that he had constantly kept himself busy with alien planets and other things, the Doctor probably wouldn't have discovered the problem for another few years despite the fact that the cats were increasingly encroaching upon his territory if it weren't for the kitten. The kitten who had been rather bolder and more curious than its littermates which had left its place in the back of the wardrobe where it had been born on one of Barbara's old cardigans and made its way to the console room. It was there that The Doctor who had been making his way to a meeting with some official or other which he would rather have skipped entirely had nearly stepped on the creature on his way out the door.

Upon spotting the feline, he assumed that it had belonged to one of the UNIT personnel who'd apparently stashed the creature aboard his TARDIS rather than be caught with it at work, and he'd rather wickedly decided to bring it to the meeting with him in order to watch its owner squirm. As he picked it up, the small creature hissed at him, baring its tiny fangs and unsheathing its diminutive claws, but he payed it no mind seeing as neither its fangs nor its claws were strong or sharp enough to puncture his skin.

Jo had been the first to notice that he was carrying the kitten which constantly tried to escape from him.

"Where did you get that darling kitten?" she exclaimed upon spotting the small calico creature, calling everyone's attention to him and his tiny burden.

"I found it in the TARDIS." he replied.

Jo's expression told him just about everything he needed to know.

"How many more of them are there?" he asked the young woman.

"I don't know. There were five of them, but if they've had kittens..." Jo replied.

"We'll deal with this after the meeting." he ground out, barely suppressing the urge to yell at the woman who'd apparently used his TARDIS as a dumping ground for stray cats.

After the long and tedious meeting at the end of which he'd gifted a certain pompous official with a certain small mammal which had caused the man to smile and comment on how it would be perfect for his granddaughter, he, Jo, and the Brigadier made their way aboard the TARDIS in order to see exactly how bad the cat situation was.

"Where exactly did you leave them?" he asked the young woman who was apologizing and using the fact that she hadn't wanted to see the poor cats euthanized as an excuse.

"I left them in that garden you showed me." she replied.

As far as The Doctor was concerned, it was no wonder he hadn't spotted the cats earlier seeing as he almost never went into that particular garden and had only shown it to Miss Grant because he'd thought she'd like it. He'd never intended for her to go dumping small animals into the room full of alien plantlife which the TARDIS carefully maintained for him.

When he remembered exactly when the base had been dealing with the feral cat problem that had led to the kitten he'd found, a rather nasty suspicion hit.

"Exactly when was this?" he asked his assistant, dreading the answer.

"Shortly before that incident with Omega." she replied.

As his body went into panic mode upon receiving confirmation of his suspicions, he raced towards the garden, practically broke the door control when he slapped the button that opened it, and peered inside.

"Good Lord!" the Brigadier who'd sprinted after him exclaimed from behind him as he got a good look at the interior of the garden where hundreds upon hundreds of cats were doing everything from eating to fighting to just simply lazing about while a food dispenser that had not been there previously spat out food pellets at irregular intervals.

The instant they noticed him and his entourage, the creatures that had made their home in his TARDIS began to scatter. Wave after wave of cats went racing off in just about every direction including up into the vents thanks to an innate climbing ability and a number of conveniently located plants.

Following the discovery of the cats, The Doctor rather quickly learned that he couldn't treat this infestation of felines like he would any ordinary infestation, and that he would have to come up with a more creative and diplomatic way of dealing with the problem if he wanted to avoid conflict with his human companions after Sergeant Benton and Captain Yates had learned exactly what it was that he'd mixed the poisoned bait for. Apparently, while Humans didn't see any problem with snapping the necks of small rodents, sticking them in glue and suffocating them in a trash bag, or just poisoning them with something that wasn't anywhere near as quick and painless as what he'd planned on using on the cats, they were rather sentimental about felines and got up in arms if you tried to kill even one of them the way you would a mouse.

Edited 7-26-13