“The boat train’s just ahead of us, sir,” he announced. “She can’t get on any better than we can. We’ve just heard that there’s a bridge down on the line between Ipswich and Harwich.”

“What are we going to do, then?” Mr. Dunster demanded.

“That’s just what I’ve come to ask you, sir,” the guard replied. “The mail’s going slowly on as far as Ipswich. I fancy they’ll lie by there until the morning. The best thing that I can see is, if you’re agreeable, to take you back to London. We can very likely do that all right, if we start at once.”

Mr. Dunster, ignoring the man’s suggestion, drew from one of the voluminous pockets of his ulster a small map. He spread it open upon the table before him and studied it attentively.

“If I cannot get to Harwich,” he asked, “is there any possibility of keeping straight on and reaching Yarmouth?”

The guard hesitated.

“We haven’t heard anything about the line from Ipswich to Norwich, sir,” he replied, “but we can’t very well change our course without definite instructions.”

“Your definite instructions,” Mr. Dunster reminded him drily, “were to take me to Harwich. You have been forced to depart from them. I see no harm in your adopting any suggestions I may have to make concerning our altered destination. I will pay the extra mileage, naturally.”

“How far did you wish to go, sir?” the guard enquired.

“To Yarmouth,” Mr. Dunster replied firmly. “If there are bridges down, and communication with Harwich is blocked, Yarmouth would suit me better than anywhere.”