Sometimes we look back on beloved cartoons and discover they have dangling plot threads or mysterious unanswered questions. Some of these details may have been left vague intentionally so that fans could decide an outcome for themselves, while other shows were left tragically unsolved when they were cancelled before writers could come up with a solution.

As we have grown up and moved on from cartoons while new generations of kids discover them, some of the biggest mysteries have been solved without us noticing.

What Happened to Arnold’s Parents? (Hey, Arnold!)

The final two-part episode of Hey, Arnold! titled The Journal left fans on an epic cliffhanger after Arnold discovered a map possibly leading to the location of his long-lost parents, Miles and Stella. The cliffhanger was intended to be resolved in the second of two planned Hey, Arnold! films, but when the first film under-performed at the box office, the second was scrapped, leaving the fate of Arnold’s parents unknown.

Thankfully, the era of the reboot gave the story a chance to be told. In 2017, Hey, Arnold! The Jungle Movie was finally released. The film revealed that while on a trip to San Lorenzo, helping their friends the Green-Eyes tribe, Miles and Stella fell victim to a mysterious sleeping sickness. After winning a school trip to San Lorenzo, Arnold manages to find and cure his parents, with a bit of help from Gerald and, surprisingly, Helga.

The movie also revealed Arnold’s last name: Shortman. A mystery hidden in plain sight, as it turned out that Short-Man, the nickname Arnold’s grandpa had for him, was a play on his surname all along.

What Happened to Zuko’s Mother? (Avatar: The Last Airbender)

While Avatar: The Last Airbender easily has one of the most satisfying endings of all time for an animated series, the show still left a few dangling plot threads; one being the fate of Zuko’s mother, Ursa. Zuko knows Ursa was banished from the Fire Kingdom, but not where she ultimately ended up.

In The Search, a three-part graphic novel taking place sometime after the series, Zuko, the now Fire Lord, enlists the rest of Team Avatar to help him find Ursa once and for all, reluctantly bringing his somewhat evil sister Azula along for the ride. To Zuko’s excitement, the group eventually finds Ursa, now going by the name of Noriko, hiding in her former hometown with her new husband Noren and young daughter Kiyi, a half-sister to Zuko and Azula.

After Zuko and Team Avatar stop Azula from attacking her new sister in a jealous rage, Zuko invites Ursa, Noren and Kiyi to live with him in the palace. They have remained a part of his royal household in later graphic novels.

What Was Inside the GS Ball? (Pokémon)

Beginning in the Orange Islands and carrying through to the early episodes of Johto Journeys, the Pokémon anime features a story arc in which Ash must deliver the GS Ball (a mysterious gold and silver Poké Ball) from Professor Ivy to Professor Oak, and later to Poké Ball expert Kurt. Neither of the Professors could work out how to open the ball, so they hoped Kurt could find some answers. Unfortunately, the show seemed to completely forget about the GS Ball as soon as Ash dropped it off to Kurt, leaving viewers in the dark as to what was inside.

In 2008, director Masamitsu Hidaka revealed that the GS Ball was originally going to contain a Celebi, but this idea was scrapped after Celebi was chosen to be the featured Legendary in the fourth film, Pokémon 4Ever. Rather than coming up with an alternate explanation, the GS Ball storyline was quietly dropped, in the hope that everyone would simply forget about it.

Why is Donald Duck Raising Huey, Dewey and Louie?

In early Donald Duck shorts, Huey, Dewey and Louie were said to have two living parents, with Uncle Donald simply acting as a babysitter. However, the parents soon disappeared, leaving Donald as his nephews’ sole guardian, with occasional help from Daisy and Scrooge. While rarely questioned in-universe, in the eyes of fans the whereabouts of the boys’ parents has been one of Disney’s greatest mysteries.

The mystery has been at least partially solved in the 2017 Ducktales reboot. Throughout the first season, Dewey and Webby investigate the whereabouts of the triplets’ mother, Della Duck. It is eventually revealed that Della dreamed of travelling to space and when the triplets were only eggs, Scrooge gifted Della with a rocket ship, The Spear Of Selene, to celebrate her sons’ impending births. Against the wishes of both Donald and Scrooge, Della takes the rocket on what she believes to be a quick trip, only to become lost in a cosmic storm and being MIA ever since. Della’s disappearance lead to a rift between Donald and Scrooge, explaining why they were not speaking at the beginning of the series. The season one finale revealed that Della was alive, albeit stranded on the Moon. In season two, Della finally makes her way home, meeting her sons for the first time.

While Della’s fate has been revealed, the identity of Huey, Dewey and Louie’s biological father remains a mystery. At this point, most fans are happy to accept that Donald has more than earned his place as the main father-figure in his nephews’ lives.

With many of us spending extra time at home, perhaps now is a good time for yourselves to experience the resolution of these classic cartoon mysteries, from Hey, Arnold!, Pokémon, and more.