I also don't really understand what's going on(just started reading it this morning)
This story really 'heavy' (in positive way)
*spoiler* not hallucinations but more like virtual reality, or very vivid dreams... they are attached to a machine that Law created called moritat (no, its not a chip) that help them to create this fake realities in their heads, why? and how? thats whats going on in the next season of this story...
Suddenly i see leonardo dicaprio movie... Which i forget its title
so the plot is just a memory or just hallucination? still dont get it.. help meeeee Σ(っ°Д °;)っ