"I am not going to explain the whole business to you, Barcroft," said the vet, when Peter expressed his regret at the attack upon his neighbour, and still more so his astonishment at finding him under most peculiar circumstances on the cliff at Scarby. "Some day, perhaps. I had information--no matter how--that some one was in traitorous communication with enemy submarines. To bring home proofs of the principal's guilt it was necessary to tackle his subordinate. Unfortunately my plans were upset by the somewhat injudicious intervention of these youngsters--commendable as regards pluck and all that, but nevertheless it spoilt my investigations." "I didn't know that you were in the detective line," remarked Peter. Entwistle shrugged his shoulders. "Perhaps I had better not commit myself by answering your question," he replied with a laugh that ended in a wince. It was no easy matter to smile with one's face smothered with sticking-plaster. "I hope you understand my reluctance to say anything more on the matter." Peter nodded. "All the same I shall look forward to the time when you are able to emerge from your shell," he said. "By the bye," remarked the vet, "you haven't told me what brought you to this part of the world. It's taking a one-sided advantage when I ask if _you_ are doing a bit of detective work." "I was," admitted Mr. Barcroft. Entwistle raised his eyebrows in mild surprise. "Tracing the persons who stole my donkey--Butterfly," continued Peter. "I had the tip that the animal had been taken to Bigthorpe. Went there to follow up the clue, and strangely enough almost the first man I met was Norton." "What was he doing at Bigthorpe?" "I hardly know. Said something about a nervous breakdown. He seemed a bit upset, I thought." "H'm!" Entwistle, gazed into the fire, deep in thought. "Is he returning to Tarleigh?" "He's there already, I presume," replied Peter. "However, that has nothing to do with the case I am relating (Entwistle thought otherwise, but refrained from audible comment). At Bigthorpe I found that Butterfly had been sold to a man at Scarby, so on I came. Quite by accident I met the fellow on the road, kept out of sight and watched him go towards the cliffs. Went and had a look at his cart, discovered it laden with petrol-cans, so I made off immediately to inform the coastguard. The rest you know." "As to that----" began the vet. The door being opened interrupted his remarks. Turning his head to see who the newcomers might be, he startled his companion by saying--"Bless my soul, it's young Barcroft." "Hullo, pater!" said Billy in astonishment. "You here? This is a regular surprise." Peter got up from his chair. "Pleased to see you, boy," he exclaimed. "As for the surprise, it's nothing. To-day has been a day of surprises. What brings you ashore?"