'Detective Pikachu' Easter Eggs  Connect to the Original Pokémon Games/Show

Detective Pikachu is chock full of Easter eggs if you know where to look for them. After all, the new movie, which takes place in a city where humans and Pokémon live side-by-side, has over 20 years worth of Poké-history to reference. But there’s one Easter egg that does more than just wink at long-time fans, it also helps situate Detective Pikachu within the larger Pokémon universe.

One expository line of dialogue about Mewtwo in Detective Pikachu has a deep connection to the original Pokémon games. In case you missed it, here’s what you need to know.

Warning: Light spoilers for Detective Pikachu ahead.

If you’ve seen the trailer for Detective Pikachu (let alone the actual movie), you know that Mewtwo plays a role in the plot, and unsurprisingly it’s a big one. From the very first scene, the 151st Pokémon makes itself known, but it may come as a surprise to learn that this is actually the very same Mewtwo you could catch at the end of Pokémon Red and Blue.

This isn’t a key plot point, and the movie never flashes back to those games or even references them directly (definitely don’t expect a Professor Oak cameo). Instead, in a scene where a group of scientists set out to find and catch Mewtwo, they tell their hired goon something along the lines of, “Mewtwo was last seen 20 years ago in the Kanto region.”

For anyone unfamiliar with Pokémon geography, the Kanto region was the setting for Pokémon Red and Blue, which first launched in 1996. In those games, you have an encounter with Mewtwo after tracking the genetically modified Pokémon down at the very end of your adventure.

The games do hint at Mewtwo’s existence prior to actually finding him. At one point, you discover an abandoned lab where scientists presumably created Mewtwo in the first place. (Side note: Mewtwo’s birthday is February 6, so mark your calendars.)

Detective Pikachu seems to be suggesting that a few years after the events of that game, Mewtwo disappeared only to resurface two decades later. Of course, Pokémon fans will probably be able to poke countless holes in this theory thanks to the various other games, movies, and TV shows that expanded the Pokémon story, but it’s still a fun little Easter egg.

Oh, and here’s one more bit of Pokémon nostalgia for you. In Detective Pikachu, the main character meets up with a young journalist who’s Pokémon is a Psyduck. For anyone who watched the original Pokémon cartoon series, this Easter egg will immediately stick out. It doesn’t seem to be drawing any bigger connections, but it’s still a fun little detail in a movie crammed full of them.

Detective Pikachu hits theaters on May 10.