Black Hawk appears in the fourth book, sent to help Billy and Machiavelli release the monsters from Alcatraz. He later appears in The Enchantress, helping Nicholas and Perenelle defeat the monsters. While fighting a giant crab, Black Hawk got knocked into the water. It is unsure whether he survived the encounter because, on the one hand, the book stated: "And they all knew that the Nereids were waiting in the water," but later on pointing out that the Nereids had left after Black Hawk killed Nereus.
- Immortality: Black Hawk gained Immortality from his Dark Elder master, and therefore does not age (though he is vulnerable to injury and poison). Unless his master chooses to take his immortality away, Black Hawk may live for thousands or millions of years.