The Hubbard Glacier is a glacier spanning through eastern Alaska and through part of the Yukon Territory in Canada. A large portion of the glacier was destroyed by Percy Jackson during his battle with the shades of Roman legionaries. On top of the glacier was a giant sized version of Camp Jupiter, Alcyoneus' headquarters.
Thanatos is being held captive at the glacier by the giant Alcyoneus. Demigods Frank Zhang, Hazel Levesque, and Percy Jackson go on a quest to rescue him in order to save Camp Jupiter and its legionnaires (as the camp is under attack of the giant Polybotes and his army). Thanatos' chains cannot be broken unless melted by the fire of life, Frank's stick. Hazel attacks Alcyoneus, while Percy defends Frank from hundreds of ghosts. Meanwhile, Frank uses his stick to melt Thanatos' chains. Percy summons a mini-hurricane while attacking the ghosts and manages to retrieve the golden eagle, the pride of the Twelfth Legion. Frank eventually frees Thanatos, and is torn between helping Percy or Hazel. Percy orders him to help Hazel. Frank transforms into an eagle and a then bear and knocks the giant unconscious. Hazel and Frank then realize Percy's difficult situation as he grows more tired, and he can no longer keep his hurricane formed as the ghosts keep attacking him. Percy tells the two to kill the giant and thrusts Riptide into the ground. The ice around him starts breaking, causing pieces of the ice fortress, shades, and Percy Jackson to go flying over the edge as Frank and Hazel watch. After defeating the giant, Hazel and Frank return to the glacier and meet up with Percy, who was unharmed.