The Wickett Sisters in Hell

Mardie Wickett never gave much thought to the possibility of an afterlife. Plodding through her earthly life was enough of a chore, working just enough to pay for good times with bad people while her brilliant estranged sister, Mili, solved murders for Scotland Yard. Now both sisters are dead and in the grave, one in Heaven and one in Hell.
Surprisingly, things aren't so bad for Mardie in the infernal burbs, until a headless corpse is discovered on the steps of Lucifer's own residence and all Hell threatens to break loose. The Devil brings Mardie and her sister together to unravel the mystery of a murdered man slain among the damned, forcing them to try and forge the friendship they never had in life. Will trying to solve the crime make or break the Wickett sisters once and for all?