Thrush is determined to crush the economies of the countries bordering the Pacific by creating new submarine smuggling lanes. They finish laying out the plans on a ship in the South Pacific. Mark swipes the plans and instigates a mutiny. April and Mark are forced to abandon ship and the plans are lost. April washes up on a tiny Island and is captured by the ruler. Mark to the rescue! Unfortunately, the ship's captain also survives the wreck and washes up on the island.

Waverly believes that a Japanese war criminal is active again. Mark and April go to Hawaii to investigate their only lead, his sister. When their informant is killed, it's obvious to Mark and to April that the sister is involved.