A couple of months ago, I played a female Watson in a stage production of Sherlock Holmes: A Drama in Four Acts. Woman doctor in 1897, bit controversial, but I loved her. Then a while back I saw Doctor Who and the Boat Race on the same weekend and my mind went "OMG!" and this happened. None of the characters need further introduction - you're about to discover them for yourselves...

It was midday, and Holmes and I walked beneath a glorious blue sky back to Baker Street from the police station. We had been keeping a companionable silence, I mulling over the arrest we had just overseen and its implications, Holmes deep in his own thoughts. As we reached the door, I noticed him looking around keenly, then turning back as though not having seen what he sought.

"Have you noticed the curiously dressed gentleman who has been appearing on the other side of the street?" He asked.

"Matching striped suit, long brown coat?"

"The very same."

"Yes, I have. He was there yesterday when I left and I tried to follow him to find out where he's coming from, or going to. But I lost him."

Holmes paused with his hand on the lock and looked at me with eyes wide in startlement.

"Watson! You surprise me; your initiative is developing beautifully. Where did he lead you?"

"South, as far as the old abattoir," I said, following him in up the stairs. "He must have gone inside because he disappeared into the dead end behind Portsmouth St, and I'm sure I heard the doors scraping open. Peculiar sound, I suppose it could have been something else, but there is nothing else that could have made such a noise. So I dove into the building, but he was nowhere to be found – and believe me, I looked everywhere. So he must have found another way out, which is strange in itself."

Holmes' eyes flicked as he pictured the surrounding streets and alleys in his head, looking for possible explanations.

"And yet you say he must have opened the doors. He may have opened and closed them without going inside, to throw you off the scent."

"I suppose."

"I do not recall anything else that could have made a scraping noise – was there anything unusual you saw?"

"No. There was absolutely nothing there."

"How singular! I think I shall take a look myself later, before it gets dark."

"You have seen him. What can you deduce about him?"

"Very little indeed. He presents a most stimulating mystery."

He took his pipe from the mantlepiece and lit it pensively. I dropped into the armchair opposite.

"His clothes are peculiar," he continued, "but it is his behaviour that puzzles me."

"Puzzles, you? Good Lord Holmes, this is remarkable indeed."

A smile played across his features behind the puffs of smoke.

"It is. He has come to Baker Street often enough for me to be sure that this residence, its occupants, or both are of specific interest to him. Yet he is no trained spy, though he has some little experience, and he travels daily outside of London. What do you make of that?"

I did not need to ask him to explain these observations; I trusted implicitly that they were correct.

"He is in the employ of a third party, at least for the moment?" I suggested.

"No, I think not."

"Well, I expect you know exactly what I think."

"I fancy I do," he sighed. "You think there is foul play afoot surrounding the boat race – not a ruse or misdirection as it was last time we dealt with rowers, but genuine foul play. Anyone wanting to get to the bottom of it could come to me for assistance and I would be able to solve the matter, which means that, as usual, I am a danger to anyone with anything to hide. You think the perpetrators have it in mind to silence me before I have had a chance to bring their unsavoury dealings to light."

My response was a single nod. Even I was aware that my concern was evident, and had been for some time. There had been hints of suspicious activity emanating from the Oxford crew, who had had one of their finest members murdered before the annual race several years ago. It was the first case Holmes and I solved together, and Holmes' name was not unknown to the present year's teams.

He regarded me narrowly.

"Out with it, Watson. You believe our strange visitor is connected, even involved in the affair."

"I believe it would be wise to take a means of defence if you go to the abattoir today."

"I intend to, Doctor – I shall take you, if you are not otherwise engaged. Could be ready at six?"