This discussion may contain spoilers!
It came out of nowhere. I was replying a comment and while trying to explain how there are an infinite number of possibilities things could have happened and I started forming a new theory based off a collective of older, smaller theories...
Let's start simple. Faith couldn't stand living under the Crooked Man any longer, so she made a plan that involved faking her own death.
As she was about to get herself a fresh start, she drugged her fuck up of a husband, keeping him in a vegetative state for days before finding a way to proceed with her plans and forge his suicide due to depression. (How this part may have played out is of little to no consequence for my theory).
Then, as part of her plan, she killed Lily and Nerissa. And used Lily's head glamoured as hers to fool everyone and get Bigby's/the office attention.
*Lily and maybe also Nerissa could be bad people.. we don't know. Or maybe something like Lily dying of overdose happened (we know from Holly an track marks on Lily's legs that she was a heavy drug user) and Nerissa and Faith came up with the plan and are working together, whatever. Maybe Nerissa is really her and Faith is just hiding or something. There are just too many possibilities that could work with the scenario that I'm suggesting. But let's continue as if both girls are dead, ok?
So, to continue around Faith glamoured herself as Nerissa and proceeded working normally, that way keeping an eye in Georgie/Vivian (who are important Crooked man employees), and free to wait for the sheriff to show up (as he undoubtedly would considering both victims worked there) and use him to reach her objectives.
The Crooked Man and his men not knowing what the hell was going on, fearing what the investigation could uncover/compromise his operations, decided to glamour Lily's corpse as Snow to frame her death on Crane, expecting the sheriff to be convinced that he solved the case before his sniffing around found his dirty (that's fucking everywhere lol). This would mean a significant loss as Crane was stealing big time from Fabletown for him but was still worth it all things considered (all out war).
*Maybe it was Faith that tried to frame Crane... Again it's another possibility that could still work. Let's just assume it was Crooky and his crew to simplify things.
Meanwhile, having no suspicion that Faith was disguised as Nerissa but knowing that she had disappeared, The Crooked Man got his men after her like crazy. He probably already had some suspicion of her beforehand. This whole situation may very well have been triggered because he was giving her a hard time or maybe even was about to take her out of the picture which got her desperate. It would explain it if Faith really murdered other Fables... to save her own skin, not that it's right in any way.
Continuing, Faith disguised as Nerissa while still under the lips sealed tries to get Bigby on Crooked's track before things get even more complicated. She probably just wants Bigby to put an end to his reign so that she as Nerissa can go on with her life.
The first time she tried it was in ep.2, when Bigby showed up in the Pudding and Pie and she directed him to the Open Arms so he could find Beauty and learn from her about the Crooked Man (Faith/Nerissa definitely didn't care about what he would find in room 207, she knew it was Crane's room but didn't know that the crew forged a whole scene for Lily's death there).
And the second time she tried it was in ep.4, when she came to Bigby's office and desperately tried to point us in the direction of the Crooked Man but failed, getting saved at point of giving up when Snow came in with the news that Beauty herself had called.
Ok, guys! If this theory turns out to be correct then, damn, Faith is getting all she wants. Bigby now stands face to face with the Crooked Man and his crew, and he is determined to bring an end to his reign. However this ends I'm hoping we get all the answers we could ever ask for and this whole mystery ties up in an epic best game ever way.
As always let me know what you guys think. I've never been this interested/invested in a game, and I've been playing PC games since the 90's. Telltale is the best!