*Disclaimer: This article contains spoilers for It: Welcome to Derry Episode 5. Readers' discretion is advised.*What's in the box? After the latest entry in HBO's It: Welcome to Derry, everyone seems to be asking this question. Episode 5, titled "29 Neibolt Street," was one of the most haunting entries in the prequel horror series yet.The episode kick-started the military operation (led by Major Leroy Hanlon) to hunt down the supernatural entity, unaware that it had already lured the town's children into the sewers, which finally resulted in Bill Skarsgård's debut as the iconic Pennywise in a chilling reveal.Derry's shapeshifting entity was pulling double duty in the latest episode of the show. While it was disguised as Matty in front of Lilly and her friends, it also manipulated Dick Hallorann into opening his box in front of his grandparents. Veteran Stephen King enthusiasts will immediately understand the weight behind Dick Hallorann’s box, though those new to the universe might wonder what it really means.Dick Hallorann's box is a concept introduced in King's Doctor Sleep. It is a psychic "lockbox" possessed by individuals with the Shining powers, who can use it to capture the ghostly inhabitants seeking their powers.More on Dick Hallorann's box in It: Welcome to Derry in our story.Exploring Dick Hallorann's box in It: Welcome to Derry Episode 5 View this post on Instagram Instagram PostDick Hallorann's box, mentioned in It: Welcome to Derry Episode 5, is less of a physical container and more of a psychological concept. As mentioned above, this box was first introduced in King's Doctor Sleep, when Hallorann recognized Danny Torrance's Shining powers and guided him on how to control them. While the 'Shining' powers might look impressive at first, every set of powers comes with its limitations, like the one in King's universe. As Dick Hallorann explains, the Shining powers also come with negative psychic memories and experiences, which must be locked away in the box.The box mentioned in It: Welcome to Derry Episode 5 contains all of Dick Hallorann's painful memories and experiences. However, Pennywise tricked Hallorann by manifesting itself as his grandpa and practically forcing him to open the box.In an interview with Decider, Chris Chalk (who plays Hallorann in the show) explains the box as:“Okay, think of this: If you had the ability to see beyond this reality since you were a wee one and you were told, ‘Put it in a box.’ So imagine all of the things we hate about ourselves, or we hate about the people across us, and we just put it down. We just stuff it, we stuff it. It’s really that.”Co-showrunner Jason Fuchs also added that once open, 'it’s not easy to close,' hinting at a dire future for the character in It: Welcome to Derry.Why did Pennywise want Dick Hallorann to open the box in It: Welcome to Derry Episode 5? View this post on Instagram Instagram PostWhile Dick Hallorann enters Taniel's mind and discovers the whereabouts of the shapeshifting entity, his Shining powers are no match for Pennywise's manipulative skills, who haunts him by disguising himself as his abusive grandfather. Hallorann's grandfather (Pennywise in disguise) repeatedly forced him to open the box, even shooting his beloved grandmother, until his bad memories were out in the open.The creepy clown wanted Hallorann to open the box to weaken him and make him unable to use his shining powers against him. While nobody in Derry could match Pennywise's powers, Hallorann's aid to the military posed a threat to the entity's powers. This is why he forced him to open the box. The opening of the box in It: Welcome to Derry Episode 5 was symbolic of Dick Hallorann reaching a dark and negative place in his life.Fuchs explained it as:''That is going to take Dick to some extremely dark places, to a place he’s tried to get away from...There’s a reason he wanted to keep that box shut. His life by the end of Episode 5 has been fully upended in ways that will take him to the breaking point and possibly past in the episodes to come.”While Fuchs' comments are ominous enough, the last shot of It: Welcome to Derry Episode 5 practically proves that the opening of the box has unleashed a darkness within Dick Hallorann. After he exits the dark sewers, he sees the dead Captain Paul in front of him, who sacrificed his life for Will moments before. This scene proves that while Dick was able to lock away ghosts and negative energy in the past, the opening of the box has unleashed all the demons from his life.It: Welcome to Derry airs weekly episodes every Sunday on HBO.For the latest scoops on your favorite TV shows and movies, follow Soap Central.