Characters in Vespers Rising

Gideon Cahill

The 16th-century founder of the Cahill line who invents the master serum and gives his life to protect it.

Madeleine Cahill

Gideon's youngest daughter, raised in secrecy as 'Maddy Babbitt,' progenitor of the Madrigal branch.

Grace Cahill

Amy and Dan's grandmother, shown here as a fourteen-year-old already in action during World War II.

Also in Maze of Bones

Amy Cahill

Returns in the present-day section, trying to settle into normal life when the Vesper threat resurfaces.

Also in Maze of Bones, One False Note, The 39 Clues, The Viper's Nest, The Emperor's Code, Storm Warning, Into the Gauntlet, A King's Ransom, The Dead of Night, The Medusa plot

Dan Cahill

Amy's younger brother, drawn back into danger as their grandmother's last legacy unfolds.

Also in Maze of Bones, One False Note, The 39 Clues, The Viper's Nest, The Emperor's Code, Storm Warning, Into the Gauntlet, A King's Ransom, The Dead of Night, The Medusa plot

Damien Vesper

Gideon's friend turned betrayer and founder of the Vespers, who covets the serum for absolute power.

Olivia Cahill

Gideon's widow who carries on his secret and raises their daughter Madeleine to one day reunite the family.

Fiske Cahill

The children's great-uncle and present-day guardian.

Nellie Gomez

The siblings' au pair, present in the modern-day section.

Also in Maze of Bones