You’ll get some additional background information about Thancred and a hefty amount of experience for your efforts, so it’s one of the more worthwhile side quests to take on. It won’t become available until you complete the Outside Help main story quest, though.
How to complete FF14 Secret in the Box quest - Solve the riddles in the letter to obtain the key
Head to Old Sharlayan, the stadium specifically. If you’re having trouble spotting the quest on your map, the coordinates are x: 10.6, y: 11.1. The Mysterious Maiden has a set of tasks for you, but you’ll have to solve three riddles first. Secret in the Box riddle 1 Or you would without this guide. Examine the letter as directed, then make your way to x7.9, y13.8 and the Sleepy Student NPC. You’ll need to “doze” in front of him, so enter the /doze command in the chat box to finish this part. Secret in the Box riddle 2 For the second riddle, go to x9.0, y7.3 and say “golden acorn” to Nutkin the squirrel. That’s the /s command in the chat box, followed by “golden acorn” (without quotation marks). Secret in the Box riddle 3 The last riddle takes you to x11.5, y8.5, where all you need to do is speak with Izumi. Head back to the Maiden, and you’ll get:
169,000 - 190,000 experience points Chondrite Ring Coffer 735 Gil
And a bit of backstory about Thancred. The rings from the coffer are common, but helpful, so it’s worth opening even if you might not need it. You can always hawk it on the marketplace anyway. That’s it for how to complete Secret in the Box in FF14. Make sure you do it all in one sitting and avoid being AFK for too long. With the state of Endwalker’s queues, the last thing you want is to be kicked out of the server. FF14 is the most profitable game in the series, and while it still isn’t on Xbox, the number of player trying to log on probably won’t be decreasing anytime soon.
