Victorian adventuress and butterfly hunter Veronica Speedwell

receives an impossible task—saving society art patron Miles Ramsforth from execution, who stands accused of the brutal murder of his mistress Artemisia.

Together with her natural historian colleague Stoker, Veronica races against time to find the true murderer—a ruthless villain who not only took Artemisia's life in cold blood but is happy to see Ramsforth hang for the crime.