When you wake up, go to the center of the village and you will see Francis there with a question mark above her head. Talk to Francis and she'll tell you what her problem is. Francis will tell you that every month, on the same day, Dr. Potan goes out somewhere without telling anyone where he's going. She asks if you can find out and says that someone saw him heading to Zoomy Lake. Don't go through the shortcut to Treely Woods, because Petasi will say that he doesn't think Dr. Potan went through there. Instead, go through the arch to Green Meadows at the southwest corner of Pupsville. You will see Dr. Potan walking along the path. Go through Green Meadows and then to Treely Woods.
You will see Dr. Potan go across the bridge and then along the path to Zoomy Lake. Go to Zoomy Lake and Petasi will say that you've got to swim to get any farther. Swimming is just like walking, except you cannot howl in the water. You need to go down to the beach, then get to the large island in the center of the lake. There are some steps leading to it, but watch out for the crocodiles in the water. Get to the steps and climb up them, and you will see Dr. Potan. Go near him to find out what the problem is.
Dr. Potan is standing near his friend's grave. He tells you what happened. He says that his friend got sick, and he was trying to make her better, but Obaba told him that his medicine would only make her worse. However, he ignored Obaba, and so his friend died. Now every month he goes to Zoomy Lake to see his friend's grave, and he thinks that she's annoyed that he let his pride get in the way, and also that he keeps looking back to the past. After his story, you will find yourself back in Pupsville, where you can tell Francis what you've learned.
Francis thanks you, and tells you that there was someone with a strange hat looking for you. Petasi wonders if it was Yi Lu.
Angry Yi Lu
Go to Green Meadows, and Yi Lu will be there waiting for you. He thinks that you are thinking that you can sniff, so you don't need his help, but in reality, you do. He tells you to go and find Ring Fragment 2, which is in Zoomy Lake.
Go to Zoomy Lake, and start sniffing. You will soon pick up a scent and the scent meter will turn pink. You will also see a trail of pawprints on the ground. You need to follow them, and they will lead to a chain of small islands in the northwestern corner of the map. You will come to a gap between one of the small islands and a path leading to the waterfall. Petasi will say that the gap is too far to jump, and it doesn't look like you can get to the path from within the lake either. Then you will see the hippo which is sleeping in a cave at the side of the lake. You and Petasi will automatically appear on an island with a tree stump on it, near the gap between the islands. You realize that this is where the hippo likes to eat. Petasi says that you need to find some Hippo Food, and you will sniff around to memorize the smell.
The Hippo Food will be on the shore near the Treely Woods entrance. Take it back to the tree stump and press to place the food down, and the hippo will come to eat. Now you can go back to the island and hop on the hippo's back to get to the path. Continue sniffing, and you will find Ring Fragment 2.
Take it back to Yi Lu, and he will sniff. He smells something. He says that it isn't you, there is something going on in the Village. Go back to Pupsville and sniff around. The village looks empty... and it smells like it is full of sick dogs!
Deliver the Deflungi
Go and see Dr. Potan, and he will tell you that there is an outbreak of the dog flu in Pupsville. He needs you to find an herb called Deflungi. While you are doing that, he'll look at the dogs, but he doubts if he can see all of them... it's times like these he wishes there were more doctors around. He tells you that you can find the Deflungi in Treely Woods.
Go to Treely Woods, and sniff along the side of the river. You should find the Deflungi around there. When you find it, Obaba will come and talk to you. She asks why you are here. After you explain the situation, Obaba tells you that Deflungi may not be enough to cure such a strong flu, and asks you to tell Dr. Potan. Though she doesn't know if he'll listen to her advice.
Take the Deflungi to Dr. Potan. He will thank you for it. "Now I might be able to cure the sick dogs, cough, cough, COUGH."
Dr. Potan has gone to rest on his bed, and Obaba comes into the room. She tells you that she can help, but Dr. Potan hates her. Dr. Potan tells her that he doesn't hate her. You will then see what happened to Dr. Potan's girlfriend, who he promised to marry, before she became ill. Obaba will say that there is bad Oglu in the river water. Dr. Potan says that she says such nonsense, and that he made an herb tea, so everyone should be all right. He says that he and Obaba should work together to help the dogs.
Dr. Potan tells you that he has found out some information on the last herb he needs to cure your sister. This herb is a White Flower and apparently it grows in Green Meadows.
The flower is a combined smell of three objects. So find the objects first and look for the White Flower in Green Meadows. It is in front of the signpost on the other side of the path from the bear, so you need to knock him out before you can get the flower. When you have it, bring it to Dr. Potan.
Now Dr. Potan has got all the herbs he needs, and he is ready to leave for Puroro Town. He can leave whenever you're ready. You can leave straight away if you want, or you can stay on the island for a while longer. You can talk to Dr. Potan at any time and select to go to Puroro Town if you want to leave. When you do, Dr. Potan will accompany you aboard El Dorado's ship back to Puroro Town.
To Puroro Town
Once you are back in Puroro Town, Dr. Potan will go and look at your sibling. He tells you that you should say hello to your neighbors. Go back to your house (and speak to the neighbors on the way if you want) and Dr. Potan will examine Emilio/Maria. But...
Dr. Potan says that this is far worse than he thought. He won't be able to cure your sibling with his herbs, but he can slow down the symptoms from getting worse. He says that he has heard of a flower called the Legendary Flower, with the ability to cure any illness, which grows somewhere on The Dog Island, though he doesn't know where, and he also doesn't know if it actually exists. You then decide to go back to The Dog Island.
El Dorado takes you back to The Dog Island in his ship, and thankfully there are no storms this time and you don't have to do any work on the ship either.