Some great research material here for fic, including the official ABC Concept Document including backstories, including this little gem:
"The relationship between Jack and Phryne is underpinned by a growing attraction and sexual tension, which is never dissipated - because it can never be consummated. It creates a spark between them but also, down the track, some moments of real poignancy as they both become aware of a grand passion that will never be.”
Someone at the ABC needs to be told this could cause serious emotional harm to their audience!
(Note to self: rewrite concept document to reinterpret the bit about the grand passion never being. Mwahahahahaaaa *twirls writerly moustache*)