By day, Mila is an acquiescent shop assistant; by night, she is a small ragamuffin bent on a life a crime. It's up to you to dissuade her from breaking into Zunari's safe to spite her father, and in return she rewards you with an Empty Bottle. Sail to Windfall Island at night, which is located on Row 2, Column 4 of the map, between Spectacle Island and Pawprint Isle. Mila only appears after you rescue Aryll from the Forsaken Fortress. Talk to Mila skulking near the potion shop to initiate the quest.
Find Mila next to the Chu Jelly Juice Shop, the island's potion shop. The potion shop is located next to the Auction House on the east side of Windfall Island.
Speak to Mila, who is a young girl with blonde hair and a patched, ragged dress. She will tell you to mind your own business and to go away.
Run away from Mila until you are far enough away for her to start walking in the opposite direction. Follow her at a safe distance, only moving when her back is turned to you. If she catches you out in the open, you will have to restart the quest.
Hide from Mila when she stops and turns at the bottom of the hill, directly beneath the arch. The best hiding spot is behind the wall on the right side near the top of the hill. Continue to hide here until she turns around and begins walking again.
Walk down to the arch where Mila stopped previously. Hide against the right side of the wall, and rotate the camera until you see Mila stop to look around. Wait until she begins walking again and then continue following her.
Follow Mila up to the wooden ramp. Remain around the last corner of the hill until she goes through the entrance to the market, or else she will spot you.
Trail behind Mila until she reaches Zunari's stall. She runs up to the safe in the back of the stall and attempts to open it.
Approach Mila once she begins working on the safe in the vendor's stall. Talk to her when the rupee symbol appears above her head.
Answer Mila's three questions with the default selected answer. She thanks you for for your help and gives you her Empty Bottle as a reward.
Catching Mila uses the same strategy on both Wind Waker and Wind Waker HD.
Once unlocked, you can complete the quest at any time during the game.
There are four Empty Bottles in the game, but you only need to obtain one to complete the main quest.
If you fail the quest, either by following Mila too closely or answering her questions incorrectly, you must wait until the next night to restart it.