We are now come to an unusual event in the history of the Doctor's post office, to the one which was, perhaps, the greatest of all the curious things that came about through the institution of the Swallow Mail.  
On arriving back at the houseboat from his short and very busy holiday the Doctor was greeted by the pushmi-pullyu, Too-Too, Cheapside and Speedy the Skimmer. King Koko also came out to greet his friend when he saw the arrival of the Doctor's canoe through a pair of opera glasses (price ten shillings and sixpence) which he had recently got from London by parcel post. And the prominent Fantippans, who had missed their afternoon tea and social gossip terribly during the Postmaster's absence, got into their canoes and followed the King out to the Foreign Mails Office.
 
So for three hours after his arrival—in fact, until it was dark—the Doctor did not get a chance to do a thing besides shake hands and answer questions about how he had enjoyed his holiday, where he had been and what he had done. The welcome he received on his return and the sight of the comfortable houseboat, gay with flowering window boxes, made the Doctor, as he said to Dab-Dab, feel as though he were really coming home.
 
"Yes," said the , "but don't forget that you have another home, a real one, in Puddleby."
 
"That's true," said the Doctor. "I suppose I must be getting on to England soon. But the Fantippans were honestly pleased to see us, weren't they? And, after all, Africa is a nice country, now, isn't it?"
 
"Yes," said Dab-Dab, "a nice enough country for short holidays—and long drinks."
 
After supper had been served and eaten and the Doctor had been made to tell the story of the pearl fisheries all over again for the benefit of his own family circle, he at last turned to the enormous pile of letters which were waiting for him. They came, as usual, from all parts of the world, from every conceivable kind of animal and bird. For hours he patiently through them, answering them as they came. Speedy acted as his secretary and took down in bird and animal the answers that the Doctor reeled off by the dozen. Often John Dolittle so fast that the poor Skimmer had to get Too-Too (who had a wonderful memory) to come and help listen, so nothing should be missed through not writing it down quick enough.
 
Toward the end of the pile the Doctor came across a very thick envelope, all over mud. For a long time none of them could make out a single word of the letter inside, nor even who it was from. The Doctor got all his notebooks out of the safe, compared and peered and pored over the writing for hours. Mud had been used for ink. The signs were made so clumsily they might almost be anything.
 
But at last, after a tremendous lot of work, copying out afresh, guessing and discussing, the meaning of the extraordinary letter was pieced together, and this is what it said:
 
"Dear Doctor Dolittle: I have heard of your post office and am writing this as best I can—the first letter I ever wrote. I hear you have a weather bureau in connection with your post office and that a one-eyed albatross is your chief weather prophet. I am writing to tell you that I am the oldest weather prophet in the world. I the Flood, and it came true to the day and the hour I said it would. I am a very slow walker or I would come and see you and perhaps you could do something for my gout, which in the last few hundred years has bothered me a good deal. But if you will come to see me I will teach you a lot about weather. And I will tell you the story of the Flood, which I saw with my own eyes from the deck of Noah's Ark.
 
"Yours very truly,     
"Mudface."
 
P. S.—I am a turtle."
 
At last, on reading the muddy message through, the Doctor's excitement and enthusiasm knew no bounds. He began at once to make arrangements to leave the following day for a visit to the turtle.
 
But, ! when he turned again to the letter to see where the turtle lived, he could find nothing to give a clue to his whereabouts! The mysterious writer who had seen the Flood, Noah and the Ark had forgotten to give his address!
 
"Look here, Speedy," said John Dolittle, "we must try and trace this. Let us leave no stone unturned to find where this valuable document came from. First, we will question everyon............