"Sinfully Rich" by Hulbert Footner is a fast-paced mystery that aims to solve a murder. Mrs Ware was a very rich woman from the upper-class society of New York. So, her untimely death shook her social circle to its core. The only thing that could make it worse is the fact that it seems uncertain whether her death was due to natural causes or by something more sinister, like a murder that must be investigated.