Heroes of Olympus and Equestria

Percy POV

Percy felt immense fear as he was falling and was also holding Annabeth's hand and the last thing that he remembered before they got in their current situation was helping to get the Athena Parthenos from Arachne and after that it was nothing but falling.

The walls of the place were dark and scary and there were plenty of ghosts flying around and he remembered about the fact that Tartarus was very dangerous but what he was experiencing now was even scarier than the descriptions he read.  The entire time they were falling, the only sound they heard was the howling and hissing of ghosts.

Although he and Annabeth might possibly plummet to their death, the good thing was that it would be worth it since one of the Doors of Death was in Tartarus and they were the key to defeating Gaea.

They continued their descent and they fell deeper and deeper into the depths of Tartarus.

Just when Percy thought that they might still have a lot more to go, a strange portal suddenly materialized and he and Annabeth were sucked into it and while falling through it, Percy wondered, "Where will it take us," and after a while, they passed to the end of the portal and when they exited it, Percy looked down and saw a town, which looked very colorful and cartoonish.  As they continued their fall, Percy noticed that the inhabitants were not human but seemed to be horses and that was the last thing he saw before he was knocked unconscious after he and Annabeth had impacted the ground.

Leo POV

Leo felt a sense of victory as the Argo II approached their destination, Epirius.  The moment of truth would come quickly once they found the temple and Gaea would pay for hurting him and his friends, he thought.  But despite feeling a sense of victory, he still felt a sense of grief for losing his friends, Percy and Annabeth into Tartarus but he new that there, hopefully they would find and close the Doors of Death there but it would be very dangerous but still, they had secured the Athena Parthenos before they fell into Tartarus but despite that, Leo feared that their sacrifice might be in vain.

However, this was not the time for fearing and they had to proceed and find and close the Doors of Death in their destination  and so, Leo speed up the ship.

As they were speeding toward the Doors of Death, a portal suddenly appeared.

Leo steered the ship, trying to avoid the portal but its suction power was too strong and the Argo II was sucked into it.

While the ship was in the portal, headed for the other side, Leo felt anger that they did not reach it but at the same time, he felt a sense of curiosity of where the portal would lead them.

Finally, the Argo II reached the other side of the portal and Leo looked at the surroundings, which looked strangely, very colorful and cartoonish.  Then, he spotted a town and steered the ship toward it.