https://www.gamespot.com/articles/fortnite-guide-search-between-movie-titles-haunted/1100-6458737/

Season 4 of Fortnite: Battle Royale is underway. In addition to taking part in matches like normal, there are a number of special challenges to complete. Beyond the regular Starter and weekly challenges, Season 4 also presents some extra ones: Blockbuster and Carbide. Here's everything you need to know and details on all of the challenges revealed so far. [Update: Season 5 begins on July 12, making this your last chance to complete these challenges and earn Season 4 skins and rewards.]

Reward: 5k XP (after completing four challenges)