Letter from a Drifting Island is a side quest in Mario & Luigi: Brothership that can be started on Shipshape Island after completing Allsand Island. Read on for a full walkthrough of Letter from a Drifting Island, including its location, unlock requirements, and rewards.

Letter from a Drifting Island Location and Unlock Requirements

Letter from a Drifting Island Side Quest
Rumor has it that something un-fishy can be seen from the fishing spot. If you fish now, maybe you'll catch it.
Unlock Requirements	Complete Allsand Island
Quest Start Location	Shipshape Island

Unlocked After Completing Allsand Island

After you complete Allsand Island, you will be able to find this side quest on Shipshape Island. Fish for the Note in the Bottle from the Fishing Spot in order to start Letter from a Drifting Island.

If this side quest doesn’t appear for you after you return to Shipshape Island from Allsand Island, you may need to progress the story a little bit.

Story Walkthrough

Fish for the Letter

The quest officially starts after fishing a letter in a bottle, possibly from a drifting island, while on Shipshape Island. The quest log suggests changing bait or Bros. if you can’t get this quest bottle, but it did work for us having both Mario and Luigi fish with a Standard Bait.

How to Fish

Letter from a Drifting Island Walkthrough

Letter from a Drifting Island Quest Objectives
Look for the Castaway's Family Head to Shroonken Islet Find the Castaway

Look for the Castaway's Family

Return to Allsand Island and immediately take the green pipe to the center of the map. Find the NPC wearing an archeologist outfit and talk to him.

After letting him know about the letter that you found, he will ask for your ocean map and mark the islet where his brother could be.

Head to Shroonken Islet

Plot a course to the current closest to the marked islet on your map and sail along its edge until you discover a hidden current. Once you're near the islet, head to the Shipshape Island's cannon and prepare for launch.

Find the Castaway

You'll immediately find a coin arrow pointing at some Twistee flowers. You know what to do! Hop on the lowest flower and follow the trail to the top, dude!

Near the summit, you will find the missing brother on a platform. Let him know that his brother is worried sick then talk to him again so you can return to Allsand Island together, completing the quest!

A few more platforms to the top and you will reach the reward the board dude at the islet's starting point was talking about, which is a Knockout Hammer.

Letter from a Drifting Island Rewards

Stache Bean and Ultra Candies

Reward	Description
Ultra Candy x2	Restores HP and BP by 70%.
Stache Bean x1	Adds 1 to STACHE.

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