On my first listen through to the chapter I was struck that Angel had found something significant in Bill's desk and I'm wondering what it could be. We know that his journal was in there but I think there was something else and I bring as my evidence the following:
@31.33: Kalani has started his final run and says "do me a favour, there's something in Bill's desk I want you to have"
To me that doesn't sound like the sort of way you talk about a journal, unless of course there is a signficant revelation inside
@44.06: Angel starts rummaging through the desk and says "Here it is [pause] what the hell is this?" before being interupted by Michael calling him back to the roof
If it was just the journal would he really have reacted in that way? He certainly didn't have enough time to read anything from it
@45.20: After Lady is put into Hope's backpack Angel says "I'll be these in there too; they are Kalani's journal"
It may be nothing but he definetely says "they" as in more than one thing
@52.13 Scratch tells Bricks "put him with the old man, I've found what I was looking for"
And if I am wrong about the previous point then perhaps the body they found is Angel's and Scratch retrieves something from him. For me though this is a weak point but its definetely a maybe particularly as she says "what" not "who" although the "what" could equally be evidence that the rat was no longer with the survivers
Also, I haven't checked back on previous chapters but didn't Tanya scan all the journals and then destroy them?
If there was something else in the desk I think it is most likely that it was a radio or something that Kalani had used to communicate with the Mallers and it will tie into revelations uncovered from his journal at the start of the next season.
My friends - the floor is yours.