Sherlock Holmes represents the main chain of story quests. The biggest rewards are given for the completion of these quests.
Dr. Watson represents additional quests that allow you to learn more about the book worlds. The rewards for completing these quests are smaller.
Quests with decorations and the image of the holiday location item are quests of the current special event, which opens a unique story.
Lucy Burk represents available quests that are connected with a holiday or special event.