"Smurfquest" was a four-part episode that appeared in Season 6 of the Smurfs cartoon show. It is considered that season's premiere episode.
As Papa Smurf reads a story to his little Smurfs on a rainy stormy night, a figure in a raincoat appears at the door. He is Grandpa Smurf, Papa Smurf's own Papa Smurf, who has come home from a 500-year journey into the world to reveal his purpose for doing so: to find the purest sources of the four primal elements -- earth, fire, water, and air -- and to use them to restore power to the Long Life Stone, a mystical stone responsible for allowing the Smurfs to live long lives. Its power is fading, and they need to restore it before its power completely fades, resulting in rapid aging and the imminent destruction of both the Smurfs and the village.
However, as Grandpa Smurf has not brought any samples of the four primal elements with him from his journeys, he and Papa Smurf get help from Homnibus, who causes a pair of boots to become magical traveling boots that will allow the Smurfs to easily travel to the places around the world where Grandpa Smurf has found the purest sources. After telling most of the Smurfs to stay behind and help find the Long Life Stone that was buried somewhere in the village, Papa Smurf with Grandpa Smurf, Hefty, Handy, Greedy, and a stowaway Sassette journey off into the world using one of Homnibus' magical boots to get to those four places.
But they don't journey off into the world by themselves. Gargamel, who has overheard Grandpa Smurf and Papa Smurf talk about the Long Life Stone, calling it their most valuable treasure, wants to get his hands on it, thinking it to be a valuable treasure that will make him rich, and so takes Homnibus' other boot in order to follow those traveling Smurfs around.
Their first stop is to the Arctic circle, where the sample of water is to be found, which is guarded by an ice elemental called Jack Frost, who immediately freezes them in ice. But when Gargamel foolishly encounters Jack Frost, he accidentally causes a chunk of ice to break the Smurfs' frozen prison, allowing them to collect the water sample and journey off to their next stop: Egypt. Inside a pyramid, they encounter snapping alligators and a Sphinx who presents them with a riddle that they must solve, which Sassette surprisingly gets right, allowing them to collect the earth sample. Gargamel, however, doesn't get it right and finds himself relentlessly pursued by the Sphinx.
Meanwhile, back in the village, the Smurfs dig furiously around to find where the Long Life Stone is located when they accidentally hit a fountain of water that nearly floods the village until they find a way to stop it from flowing. But it surprisingly pays off for them, when they discover a magic box that contains the stone. Unfortunately, they can't break into the box to open, which means they will have to wait for someone with the key to open it.
The next stop in the traveling Smurfs' journey is Japan, where they enter a temple that a powerful cyclone chamber is located in. Hefty bravely enters this chamber and finds himself being uncontrollably tossed about until he succeeds in collecting the air sample. Gargamel reaches the temple, but all he gets is a whirlwind blowing him away. The final stop for the Smurfs is an island off the South Seas where the fire sample is waiting for them inside a volcano. But the way to the volcano is blocked by a tribe of warriors vaguely resembling Easter Island Moai heads. The Smurfs find a way to distract them long enough to climb the steps to the top of the volcano. But as they race to the top, something happens to the Smurfs: they are beginning to age very quickly. Grandpa Smurf realizes that the power of the Long Life Stone is fading, and if they don't get the final sample and get it home fast, their lives will soon be over. Back in the village, various Smurfs also feel the effects of the Long Life Stone's power fading, as wrinkles, gray hair, failing eyesight, and other advancing age elements come upon them at a rapid pace.
The traveling Smurfs succeed, just barely, in collecting the fire sample, but as they head back to where they left the magical boot, they find out that it is gone. They discover that Gargamel has been following them, and now has the boot in his possession. They follow him up to the volcano, where he destroys the first boot, but as Gargamel nearly falls into the volcano and the Smurfs try to save him, they end up with the other magical boot as he barely lands safely away from the lava. They quickly jump into the boot as it takes them back home.
The aging Smurfs that were left in the village are glad to see the traveling Smurfs return with the four element samples, but now they need the key to open the box where the crystal is inside of. As Grandpa Smurf fumbles through the things in his beard to find the key, some Smurfs start seeing the village begin to fall apart. But soon he finds the key and opens the box, where they find the Long Life Stone shrinking to nothing. Grandpa Smurf pours the four primal element samples onto the stone, which soon regenerates the stone, restoring its power and thus causing the Smurfs to revert back to their young, vital selves. But Grandpa Smurf collapses, his life seemingly spent bravely completing the task that took him 500 years to accomplish. Fortunately, Grandpa Smurf is not gone for good, and as he revives, the other Smurfs invite him to stay in the village, which he accepts. But faraway on that South Sea island, Gargamel is pedaling a boat furiously to escape the Moai head warriors who are chasing after him, again cursing the Smurfs and hoping to get them if that's the last thing he ever does.
- This was the first of two four-part episodes that aired in the entire cartoon series, both of which would introduce new characters to the main cast. The following season's four-part episode, "Smurf On The Wild Side", would introduce Wild Smurf.
- It is not known if Wild Smurf, who would not be introduced until Season 7, was ever affected by the Long Life Stone's power fading, or how he was.
- Factoral error: Grandpa said that it has been 500 years since he has eaten Smurfberries, but their existence was not known to the Smurfs until after the events retold by Papa Smurf in "Smurfs at Sea," which took place many years before the creation of Smurfette.