A vampire who is deeply connected to Diana, Matthew struggles with secrecy and past traumas. Known as Matthew Roydon in the 16th century, he is an essential figure in the narrative, balancing his historical life with his modern identity.

Matthew's stepfather, who possesses a commanding presence and deep intuition. Philippe plays a crucial role in Diana and Matthew's lives, offering guidance and support.

Matthew’s loyal relative and protector with a fierce appearance, who silently looks after Diana through time. Gallowglass is a constant guardian figure throughout the story.

A daemon and real historical playwright with a close, complex friendship with Matthew. Kit's jealousy and suspicions of Diana create tension and danger.

This group includes historical male poets, scientists, and thinkers who provide Diana with companionship and critical aid during her time in the past.

An influential woman in alchemy who becomes a friend and mentor to Diana. Mary assists Diana with her scientific endeavors and provides emotional support.

An elder witch and a weaver who becomes a crucial mentor to Diana, teaching her essential magical skills. She provides Diana with invaluable knowledge about her unique magical abilities.

A young orphan taken in by Diana and Matthew. Annie, once disguised as a servant, is treated as a daughter and educated under their care.

A street-smart orphan who becomes part of Diana and Matthew's household. Jack develops a close filial bond with Matthew, who helps him cope with past traumas.

A powerful vampire leader who oversees a faction of creatures in London, with significant influence due to his blood rituals. He becomes involved with Diana and Matthew due to his connections and agreements.