“Now, sir, I must ask you more particularly what this document is, and why its disappearance should have such momentous consequences?”

The two statesmen exchanged a quick glance and the Premier’s shaggy eyebrows gathered in a frown.

“ Mr. Holmes, the envelope is a long, thin one of pale blue colour. There is a seal of red wax stamped with a crouching lion. It is addressed in large, bold handwriting to⁠—”

“I fear, sir,” said Holmes, “that, interesting and indeed essential as these details are, my inquiries must go more to the root of things. What was the letter?”