"great heavens!" cried the doctor, springing up. "the pearls gone? and they were registered, too!"

"yes," said speedy, "here's the thrush himself. he'll tell you all about it."

and going to the door, he called in the bird who had carried the registered package.

"doctor," said the thrush, who was also very upset and breathless, "it wasn't my fault. i never let those pearls out of my sight. i flew straight off for the harmattan rocks. but part of the trip i had to go over land, if i took the shortest cut. and on the way i saw a sister of mine whom i hadn't met in a long time, sitting in a tree in the jungle below me. and i thought it would be no harm if i went and talked to her a while. so i flew down and she was very glad to see me. i couldn't talk properly with the string of the package in my mouth, so i put the parcel down on the bough of the tree behind me—right near me, you understand—and went on talking to my sister. and when i turned around to pick it up again it was gone."

"perhaps it slipped off the tree," said the doctor, "and fell down into the underbrush."

"it couldn't have," said the thrush. "i put it into a little hollow in the bark of the bough. it just couldn't have slipped or rolled. somebody must have taken it."

"dear me," said john dolittle. "robbing the mails; that's a serious thing. i wonder who could have done it?"

"i'll bet it's jack wilkins, the cross-eyed pearl fisherman," whispered dab-dab. "a man with a face like that would steal anything. and he was the only one, besides us and speedy, who knew the pearls were going through the mails. it's wilkins, sure as you're alive."

"i wonder," said the doctor. "they do say he is a most unscrupulous customer. well, there's nothing for it, i suppose, but that i should paddle back to fantippo right away and try to find him. the post office is responsible for the loss of registered mail, and if mr. wilkins took those pearls i'm going to get them back again. but after this we will make it a post office rule that carriers of registered mail may not talk to their sisters or anyone else while on duty."

and in spite of the lateness of the hour, john dolittle said a hasty farewell to chief nyam-nyam and started off by moonlight for fantippo harbor.

in the meantime, speedy and the thrush flew over the land by the short cut to the post office.

"what are you going to say to wilkins, doctor?" asked dab-dab as the canoe glided along over the moonlit sea. "it's a pity you haven't got a pistol or something like that. he looks a desperate character and he isn't likely to give up the pearls without a fight."

"i don't know what i'll say to him. i'll see when i get there," said john dolittle. "but we must be very careful how we approach, so that he doesn't see us coming. if he should pull up his anchor and sail away we would never be able to overtake him by canoe."

"i tell you what, doctor," said dab-dab, "let me fly ahead and do a little spying on the enemy. then i'll come back and tell you anything i can find out. maybe he isn't on his schooner at all at present. and we ought to be hunting him somewhere else."

"all right," said the doctor. "do that. it will take me another four hours at least to reach fantippo at this pace."

so dab-dab flew away over the sea and john dolittle continued to paddle his canoe bravely forward.

after about an hour had passed he heard a gentle sort of whispered quacking high overhead and he knew that his faithful housekeeper was returning. presently, with a swish of feathers, dab-dab settled down at his feet. and on her face was an expression which meant great news.

"he's there, doctor—and he's got the pearls, all right!" said she. "i peeked through the window and i saw him counting them out from one little box into another by the light of a candle."

"the villain!" grunted the doctor, putting on all the speed he could. "let's hope he doesn't get away before we reach fantippo."

dawn was beginning to show before they came in sight of the ship they sought. this made approaching the schooner without being seen extremely difficult. and the doctor went all the way around the island of no-man's-land, so as to come upon the ship from the other side, where he would not have to cross so large an open stretch of sea.

paddling very, very softly, he managed to get the canoe right under the bow of the ship. then, tying his own craft so it couldn't float away, he swarmed up the schooner's anchor chain and crept on to the boat on hands and knees.

full daylight had not yet come and the light from a lamp could be seen palely shining up the stairs which led to the cabin. the doctor slid forward like a shadow, tiptoed his way down the stairs and peered through the partly opened door.

the cross-eyed wilkins was still seated at the table, as dab-dab had described, counting pearls. two other men were asleep in bunks around the room. the doctor swung open the door and jumped in. instantly wilkins sprang up from the table, snatched a pistol from his belt and leveled it at the doctor's head.

"move an inch and you're a dead man!" he snarled.

the doctor, taken aback for a moment, gazed at the pistol muzzle, wondering what to do next. wilkins, without moving his eyes from the doctor for a second, closed the pearl box with his left hand and put it into his pocket.

while he was doing this, however, dab-dab sneaked in under the table, unseen by anyone. and suddenly she bit the pearl fisherman in the leg with her powerful beak.

with a howl wilkins bent down to knock her off.

"now's your chance, doctor!" yelled the duck.

and in the second while the pistol was lowered the doctor sprang onto the man's back, gripped him around the neck, and with a crash the two of them went rolling on the floor of the cabin.

then a tremendous fight began. over and over and over they rolled around the floor, upsetting things in all directions, wilkins fighting to get his pistol hand free, the doctor struggling to keep it bound to his body, dab-dab hopping and flying and jumping and flapping to get a bite in on the enemy's nose whenever she saw a chance.

at last john dolittle, who for his size, was a very powerful wrestler, got the pearl fisherman in a grip of iron where he couldn't move at all. but just as the doctor was forcing the pistol out of his enemy's hand, one of the other men, who had been aroused by the noise of the fight, woke up. and, leaning out of his bunk from behind the doctor's back, he hit him a tremendous blow on the head with a bottle. stunned and senseless, john dolittle fell over in a heap and lay still upon the floor.

then all three men sprang on him with ropes and in a minute his arms and legs were tied and the fight was over.

when he woke up the doctor found himself lying at the bottom of his own canoe, with dab-dab tugging at the ropes which bound his wrists to get him free.

"where is wilkins?" he asked in a dazed, sleepy kind of way.

"gone," said dab-dab; "and the pearls with him—the scoundrel! as soon as they had dumped you in the canoe they pulled up the anchor, hoisted sail and got away. they were in an awful hurry and kept looking out to sea with telescopes and talking about the revenue cutter. i guess they are wanted by the government for a good many bad deeds. i never saw a tougher-looking crowd of men in all my life. see, i've got the rope around your hands free now; you can do the rest better yourself. does your head hurt much?"

"it's a bit dizzy still," said the doctor, working at the rope about his ankles. "but i'll be all right in a little."

presently when he had undone the cord that tied his feet, john dolittle stood up and gazed over the ocean. and there, on the sky line, he could just see the sails of wilkins' schooner disappearing eastward.

"villain!" was all he said between his clenched teeth.