Sin, the Yard's top crime-busting team - so-called from the initials of its oddly assorted members - is called in to investigate a bank robbery. When Nicodemus, the pompous member of the trio, is implicated in the raid, Sherrey is forced to suspend him from duty. Inch refuses to believe the accusation and continues the investigation alone. His inquiries reveal a tightly woven mesh of intrigue and murder - and Nicodemus's delectable sister.