Murder at the Midnight Ball

You're invited to the murder of the Season.
James Poyntz is happy to see his cousin Emma presented to court. Of course, his aunt and uncle are over the moon. It's a magical night, until a man dies in the gardens during the ball and everyone present is a suspect.
After her husband's arrest, Wilhelmina Allen is tired of being helpless. Determined to help other women stuck in their marriages, she opened her own detective agency. But despite being open for months, she hasn't quite had as many high-profile cases as she's hoped for.
With a killer on the loose and the police focusing only on one suspect, Wilhelmina is the perfect person for James to turn to for help with such a sensitive matter.
But can they catch the killer before an innocent person takes the fall?