"Holmes, I cannot see any conceivable reason why a house-sized prehistoric creature would wish to make a noise like a trombone."
"These creatures were not the sharpest of sorts, Watson. Some of them needed secondary brains in their abdominal regions to remain capable of coordinating their movements. It is also true that large creatures do not necessarily have acute senses; the rhinoceros is notoriously short-sighted, and relies on its sharper sense of hearing to detect approaching hunters.
"Consider, then, a herd of such creatures. Like African herbivores, they might not all be members of the same species. Multiple species of African antelope often gather at the same water-hole to drink. However, our antelope weigh five tons and are only marginally cleverer than the pond scum they are lapping up. It is quite possible that they might elect to mate with the wrong species if they are not provided with some constant audible cue. Some species of hadrosaur might therefore have made noises like trombones, as if to say, Here I am! I am a trombone-crested hadrosaur, and other trombone-crested hadrosaurs may profitably choose to mate with me. But the noises they made would not be of interest solely to their mates. They might also have interested their predators."
"Good God, Holmes," I cried. "Are you telling me those poor wretches died simply because their instruments made sounds resembling that creature's natural prey?"
"I not only believe it," said Holmes, "I intend to prove it, by the most direct means possible."
He drew out the trombone from his bag, along with a copy of the sheet music for Thaxted.
"You will not need your pistol, Watson. It would be entirely useless against the creature. Shooting it accurately in the brain would be as hard as hitting a bull from a hundred yards, and I imagine even four-five-five ball would simply bounce off its scaly hide."
We were walking through a wilderness of winter-deadened trees, in a fog in which an entire herd of hadrosauridae could have stood shoulder to shoulder unobserved. A bandstand loomed out of the murk. Posters announced a forthcoming event involving royalty.
"There do not seem to be any dinosaurs in the vicinity, Holmes. I feel sure that such large animals would advertise their presence."
"A predator," said Holmes, "never advertises its presence." And he raised the trombone to his lips, and blew out the final bar of Thaxted. A tear rose to my eye at the thought of the country all of whose ways are gentleness, all of whose paths are peace.
Then the hairs at the back of my neck stood on end as I heard a distant, clumsy crashing from far away in the fog, as if a drunken coachman were attempting to drive an omnibus through heavy brush.
"The hunter's afoot," said Holmes. "And it is we who are the game." He motioned to me to follow as he stole away.
"Confound it, Holmes! I hadn't expected your damnable theory to actually be correct!"
"My theories, Watson, are always correct." With that, he plunged into a nearby drain or ha-ha and squelched ponderously along it, not appearing in any hurry to get to the other side. "Into the water, Watson. In this fog the beast will hunt by scent."
I have no shame in relating that I piled into the water more smartly than I have ever piled into water before, particularly since I heard, at a somewhat lesser distance now, the immense crackling whisper of something dreadfully, fearfully heavy walking across the carpet of fallen leaves on the Heath towards our former position. Walking slowly, and appearing to deviate to left and right, like a questing hound. I believe I actually heard breath, escaping like a head of steam from a ship's boiler.
"Do not make a sound, Watson, for your life depends on it."
Holmes claims that he still saw nothing at that point-I would have been able to see nothing even had the beast been standing right next to me, for I had my eyes tight shut. But at that point, we heard another sound, deep and sonorous, singing out through the fog-the sound of the low notes of a violin. It is difficult to convey how I knew purely from the sounds I heard through the mist that a Mesozoic lizard was cocking its head on one side, but somehow I knew this was what was happening, as if a bird on a branch had heard another bird whistle, or a dog heard its owner call.
We heard it plunge away through the fog.
"As I suspected," said Holmes. "There are two hadrosaur species."
We sat in the pleasant surroundings of the Jack Straw's Castle inn near the flagstaff on the northern perimeter of the Heath. Warm beer was a welcome antidote to the cold.
"I cannot understand, Holmes, how the fact that there were two species of hadrosauriwhatsit can possibly be significant."
"Quite simple, I imagine. The first species, whose calls sound like those of a trombonist executing the final bars of Thaxted, are our megalosaurus's preferred prey. The second species, meanwhile, whose call is more violinlike, are a related animal which moves with the herds of the first. But our carnivore will not attack this second species."
"It will not?"
"I will stake my life on it. These animals are not prey. Their flesh is shunned by our megalosaurus, which will nevertheless follow them in much the same way a lion will follow an animal it is incapable of bringing down, such as a rhinoceros, in the hope of finding other herbivores it can bring down. Nevertheless, Watson, whoever is controlling this creature is playing fiddle with the Devil. And he is about to walk through that door, right about-now."
The doors opened to admit a shabby-looking street musician, similar in appearance to the poor devil I had examined only a day earlier.
"Mr. Green, I believe," said Holmes. "Formerly music teacher to the family of Professor Challenger of Enmore Park. No, don't trouble yourself to pull out that revolver. You will find that almost every person in this hostelry right now is an armed member of Her Majesty's Metropolitan Police."
Eerily, as if Holmes were some macabre puppeteer, every single one of the establishment's customers turned round and raised their hats to the newcomer.
"You will perhaps be mystified as to how I know your name. You are, of course, an adherent of the Fenian cause and a proponent of Home Rule for Ireland. The merits or demerits of that question I leave to politicians. I involve myself only at the point when people believe their political causes justify murder. Your principal mistake was in presenting yourself, in disguise, to your former employer as a meat wholesaler of the name of Glass. 'Glas,' as Watson doubtless does not know but I certainly do, is the Gaelic for Green, a childish conceit which led to your downfall. You noticed several months ago whilst tutoring Professor Challenger's children that the notes of the trombone appeared to induce a blind killing rage in the juvenile megalosaurus chained up at the other end of the drawing room. The notes of the violin, meanwhile, served only to attract its attention and cause it to follow the violinist round the room. It was after learning these facts that you formulated your plan.
You planned to remove the beast from confinement using two of your Fenian confederates, and train it to attack human beings. The small number of bites inflicted on his serving staff had convinced Challenger that the creature did not seek out human beings as prey; it needed to be taught to do so. And you, Mr. Green, have been teaching it to kill for the last twelve months. And why have you been doing so? Why, in only one week's time, His Majesty King George is due to attend an open air concert at the Parliament Hill bandstand on the Heath, where the final piece on the programme will be Mr. Spring-Rice's inspired lyrics to Thaxted by Gustav Holst. In fact, it is only the final note of that tune that sets off the beast, am I right?" Holmes began whistling the final few bars of Thaxted.