I have taken nearly 3 days to roughly sketch out the basic intricacies of the plot and characters.
If the complexities of Act 1 are important to get right, then Act 2 should be a relative romp. With the Act 1 situation set and the characters hopefully well defined and the 6th character introduced and offering a twist, we can then be propelled forward into a rollercoaster of events throughout Act 2.
At the end of Act 2 the main 2 characters will reach a stage whereby their fate is linked irrevocably and must be resolved in Act 3. At the conclusion of sketching Act 1 I was fairly clear as to how this Act 3 resolution would occur, but there are some issues around Act 2/Act 3 that need surmounting.
I need a head-clearing weekend to sort out some novel issues.