Gratuitous.

[northern_magic]

So I was reading Flatterland. Which is quite excusable, seeing that a) I'm writing a fic based on a virtual continent in Flatterland, and b) every page is filled with geometry or physics and mind twisting dimensional stuff. (You do not read this book for the brilliant character development.)
And then I came upon a particular scene that, well...begged to be Doctor/Companion (namely Nine/Rose) banter. All I really had to do was copy the beginning and dialogue verbatim, replace a few names and twiddle with the wording, and voila! Instant and very weird ficlet.

Where there is catfood, there will be a cat. (Often the same one.)

Rose looked apprehensively around, but the animal was nowhere to be seen. She walked round the bowl of catfood. On the other side, it read 'INGER'.

'Why does the bowl say INGERSCHRÖD?'

'Rose, that says SCHRÖDINGER.'

'Manufacturer?'

'No.'

'Catfood advert?'

'No.'

'Logo?'

'No.'

'The cat's called Schrödinger?'

'Nope.'

'Oh.'

'Maybe the cat dings schrös.'

Rose quietly re-evaluated her judgement of the Doctor's sanity, and took a breath.

'Dings?'

'Rings like a bell.' Not a beat was missed. But the pressing question:

'Schrös?'

'A bit like shrews, probably.'

'Oh.' The conversation lapsed into an awkward silence. Finally, Rose decided that the Doctor's stance was a little too smug to be the standard I imparted knowledge to the ignorant little ape. 'Doctor, you made that up! You have no idea what the name means, do you?'

'Well, don't complain to me,' said the Doctor, arms wide and accent indignant. 'Of course I know what the name comes from. But here's the cat himself. Why don't you ask him?' 
The original text is here if you want to compare things- really, there's not much to compare.