“Um, hold on, then, you guys,” Hazel said nervously. “Arion, giddyup!”
Arion shot toward the glacier like a runaway rocket, barreling straight across the slush like he wanted to play chicken with the mountain of ice.
The air grew colder. The crackling of the ice grew louder. As Arion closed the distance, the glacier loomed so large, Hazel got vertigo just trying to take it all in. The side was riddled with crevices and caves, spiked with jagged ridges like ax blades. Pieces were constantly crumbling off—some no larger than snowballs, some the size of houses. When they were about fifty yards from the base, a thunderclap rattled Hazel’s bones, and a curtain of ice that would have covered Camp Jupiter calved away and fell toward them.
“Look out!” Frank shouted, which seemed a little unnecessary to Hazel.
Arion was way ahead of him. In a burst of speed, he zigzagged through the debris, leaping over chunks of ice and clambering up the face of the glacier.
Percy and Frank both cussed like horses and held on desperately while Hazel wrapped her arms around Arion’s neck. Somehow, they managed not to fall off as Arion scaled the cliffs, jumping from foothold to foothold with impossible speed and agility. It was like falling down a mountain in reverse.
Then it was over. Arion stood proudly at the top of a ridge of ice that loomed over the void. The sea was now three hundred feet below them. Arion whinnied a challenge that echoed off the mountains. Percy didn’t translate, but Hazel was pretty sure Arion was calling out to any other horses that might be in the bay: Beat that, ya punks!

The Son of Neptune, Chapter XLIII