Cast at a glance update, August 8:

The family:
Septimus Hambley - the deceased/status unknown
William Hambley - Septimusís son
Octavus Hambley - Septimusís younger brother

The guests:
Lady Evangeline Ames - Williamís betrothed
Andrew Keating - Williamís love interest
Phillip Hunt - some bloke Septimus knew
Mr. Bailey - very old friend of Septimus
Mrs. Bailey - Mr. Baileyís elderly wife

The servants:
Mr. Hastings - butler
Mrs. Wiggins - housekeeper
Julia North - ladyís maid
Thomas - first footman
Clarence - second footman
Jem - head groom
Lucy - scullery maid
Dulcey - hall boy (?)

Others:
Pepin Leveque - the detective
Robert Payne - the doctor
Unknown - pirate without a head in Septimusís clothes and bedroom
Willie Blackmoor - dockhand or pirate, working for Septimus
Ernie Corning - dockhand or pirate, working for Septimus

Mentioned but not seen:
Alphonse - Hastingsí former lover
Quinitivius Hambley - Williamís grandfather on his fatherís side
Quatavius Hambley - Williamís great-grandfather on his fatherís side