With release Fortnite In Chapter 6, Season 1, we got a brand new map, new weapons, new characters and new medallions. Along with these additions, there are also a bunch of new quests that you can complete to earn lots of XP. These quests aren't too hard to complete, so they're definitely worth doing.

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Fortnite: Chapter 6 Season 1 – Story Guide
The magic is awakening!
Among the numerous quests available is Wintervestigation where you will have to meet Noir and take on his cases to help solve them. At the time of writing this guide, all cases are now available for completion. That last one might leave you scratching your head, but don't worry—we've got you covered right here.
How to find Sgt Winter's secret files
Before you can start this quest, you must have completed the previous cases in Wintervestigation by Noirwhich is located at Seaport middle building, in the penthouse.
If you have completed the previous cases, there will be a final case Case #63, which is Double checked list.
Noir will ask you to find secret files for Sgt. Winter's Naughty or Nice list. To do this, head to Foxy Floodgatewhich is located just west of its location.
Once you get to this area, make your way seweragewhich can be entered through the room with the blue door on the southeast side of the location.
Inside, jump off and head right to find locked gate. Destroy it with your pickaxe.
Follow the path in front of you until you are reach three black cabinets. Communicate with all three until a scroll will appear from one of them. Once that happens, interact with the scroll twice.
For the last step you have to confront Sgt. Winter about it. It is located right now south of Foxy Floodgatenear the plane wreck.
Communicate with him and once the conversation is complete you will complete this quest and earn 25,000 XP.

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Fortnite: Chapter 6, Season 1 – Weekly Quest Guide
Explore the map, collect loot and become the shogun of sweet rewards.