If you're stuck, I'd recommend double checking that characters don't have anything new to say on repeated conversations in other branches.
If you're really stuck, here's a full spoiler answer to where you might have missed things (in rot13):
lbh trg bar frrq sebz vafcrpgvat gur ybg nsgre pyrnevat gur pbapergr, nabgure sebz gur jryy cnfg gur oevqtr, naq svanyyl ynhen tvirf lbh bar va gur pbairefngvba jurer fur yrnirf naq lbh ner cebzcgrq gb jnvg ercrngrqyl