The main characters in this book are:

• Dr. Henry Jekyll, a medical doctor and scientist
• Edward Hyde, Dr. Jekyll's mysterious friend and heir
• Gabriel John Utterson, Dr. Jekyll's old friend and lawyer
• Hastie Lanyon, Dr. Jekyll's childhood friend and doctor
• Poole, Dr. Jekyll's butler
• Richard Enfield, Mr. Utterson's young cousin
• Inspector Newcomen, a Scotland Yard detective
• Mr. Guest, head law clerk to Mr. Utterson
• Sir Danvers Carew, A Member of Parliament
• Sarah, a housemaid

This book begins when Mr. Utterson and Mr. Enfield are taking a walk in London. Mr. Enfield describes a traumatic incident he witnessed in the area they were in. A man had trampled over a little girl. The man's name was Mr. Hyde. Mr. Hyde had paid the parents of the girl to not tell anyone about the incident. He went into a scary looking door and came out with a check for the...