On the Wednesday morning following Mr. Ludgrove’s visit to Suffolk, a man walked into his shop and rapped upon the counter. The herbalist emerged from the back room at the summons, and, as was his habit, glanced gravely at his customer. He saw before him a youngish man, immaculately dressed, who immediately turned towards him interrogatively. “ Mr. Ludgrove?” he said.

The herbalist bowed. “That is my name,” he replied. “Can I be of any service to you?”

The stranger placed a card upon the counter, with an apologetic gesture. “I’m Detective Inspector Whyland, attached to the F Division,” he said. “And if you could spare me a few minutes, I should be very grateful. I’m awfully sorry to have to intrude in business hours.”