“So when I saw the outline of a naturalist and accordingly thought of Darwin, the greatest naturalist of all, it was a logical step to think back to Darwin’s historic voyage ― one of the world’s great voyages on perhaps science’s most famous ship ― the voyage of naturalistic exploration on which Darwin formulated his theory of the origin of species and their perpetuation by natural selection. And thinking back to that produced a really wonderful result.” Ellery gripped the back of a chair, leaning over it. “Because the ship on which Charles Darwin set sail from Plymouth, England, in 1831 on that epic voyage was named... H.M.S. Beagle.”
“Beagle.” Laurel goggled. “ The dead dog!”
“There were a number of possibilities,” Ellery nodded. “In sending Hill a beagle, the sender might have been providing the master key which was to unlock the door of the warnings to come ― beagle, Darwin’s ship, Darwin, evolution. But that seemed pretty remote. Neither Hill nor Priam was likely to know the name of the ship on which Darwin sailed more than a hundred years ago, if indeed they knew anything at all about the man who had sailed on it. Or the plotter might have been memorializing in a general way the whole basis of his plot. But this was even unlikelier. Our friend the scientifically minded enemy hasn’t wasted his time with purposeless gestures.
“There were other possibilities along the same line, but the more I puzzled over the dead beagle the more convinced I became that it was meant to refer to something specific and significant in the background of Hill, Priam, and their enemy. What could the connection have been? What simple, direct tie-up could have existed among a naturalist and two nonscientific men, and the word or concept ‘beagle,’ and something that happened about twenty-five years ago?
“Immediately a connection suggested itself, a connection that covered the premises in the simplest, most direct way. Suppose twenty-five years or so ago a naturalist, together with Hill and Priam, planned a scientific expedition. Today they would probably use a plane; twenty-five years ago they would have gone by boat. And suppose the naturalist, conscious of his profession’s debt to the great naturalist Darwin, in embarking on this expedition had the problem of naming, or the fancy to rename, the vessel on which he, Hill, and Priam were to be carried on their voyage of naturalistic exploration...
“I suggested to Lieutenant Keats,” said Ellery, “that he try to trace a small ship, probably of the coastal type, which was either built, bought, or chartered for purposes of a scientific expedition ― a ship named, or renamed, Beagle which set sail from probably an American port in 1925 or so.
“And Lieutenant Keats, with the co-operation of various police agencies of the coastal cities, succeeded in tracing such a vessel. Shall I go on, Mr. Priam?”
Ellery paused to light a fresh cigaret.
Again there was no sound but the hiss of the match and Priam’s breathing.
“Let’s take the conventional interpretation of Mr. Priam’s silence, Lieutenant,” said Ellery, blowing out the match, “and nail this thing down.”