An NYPD officer facing personal tragedy following the death of his daughter, who becomes entangled in complex scientific discoveries throughout the story.

A successful businessman and innovator with a dark past, who aims to exploit a scientific invention for his own gain.

Slade’s loyal second in command, known for his neat and friendly appearance, yet capable of carrying out harsh orders.

Helena’s subsequent employer, who is optimistic about harnessing technology for global betterment but cautioned against potential consequences.

Barry's ex-wife who shares a strained but cordial relationship with him, impacted by shared grief over their daughter's death.

Barry and Julia’s daughter, whose presence or absence in timelines affects her parents' lives, remembered for her strong will and kindness.