Hiccup and the other teens began to teach Aeryn Norse, right after Snotlout left for Berk. Hiccup, Fishlegs and Astrid took charge of reading runes, while Ruffnut and Tuffnut were teaching him how to speak Norse. Within a day, it was unbelievable how quickly Aeryn had got the grasp of the beginning of basic things. Though in the evening Aeryn disappeared, to his horde.
"Well, where is he? Where is my long-lost son?!" Stoic exclaimed the next day in the morning, getting off Thornado.
"Huh ... funny story ... dad ... he left last night." Hiccup rubbed the back of his head sheepishly.
"Hiccup, is this some sort of joke!?" Stoic shouted at the small boy. "Do you have any idea what sort of pain it cost me to lose a son when you two were born?!"
"No, dad, we actually did see him. Listen to me—"He didn't finish his sentence because the next thing that happened was a blur. Hiccup fell to the floor and Stoic was held by his throat in the air, unable to get out of the unbelievable grip.
Everyone gasped as they saw the same green eyed, brown haired, boy in loincloth holding up his father, though he didn't know that, with one hand and standing in a defensive stance over his twin.
"Aeryn put him down, please." Hiccup said, getting up, slightly gaping at his twin's unbelievable strength.
"He ... hurt ... you." Aeryn tried to put a sentence together. Pointing to Stoic then Hiccup.
"Put him down." Hiccup said, softly, and the wild dragon boy obeyed. "You see, Aeryn, he's our..." Hiccup gestured to both of them. "...father." Hiccup gestured to his green eyes and pointed to Stoic's, then the hair to Stoic's beard, and pointed to Aeryn's muscles to Stoic's muscular arms.
"Me ... have ... no ... father." Aeryn said coldly and ran off back into the darkness of the trees.
"See, he exists." Hiccup said, hopefully, to the guilty looking Stoic.
Stoic gave the teens permission to stay on the island and teach Aeryn Norse and show him the Viking world when he was ready. The news that Stoic's long lost son was finally discovered spread like a wild fire across Berk, as well as the fact that he was raised by dragons all this time. The new spread from villager to villager, villager to trader, trader to other tribes, and so the news reached Alvin of the Outcasts.