I see a pattern among my readers, specifically where they tend to stop reading - it is about 2/3 through the story, during "Act 2." A few readers push through to the end and say they are glad they did. One wanted the end longer (which may be saying a similar thing; she liked the end better, but thought it felt too rushed.). There may be a pacing problem, it's not clear. The ending sounds correct as is, to me, and the problem seems to be the middle.
I'm wondering how to liven up that slow spot in the middle. No one seems to know why they lose interest. I am guessing the pacing is just too slow, or the tension is not high enough.
Here are a few ideas about how to fix this - but so far, implementing these has not solved the problem, These ideas, in no particular order:
shorten and tighten the areas where people are getting bogged down.
remove anything they do not need (variation of #1).
Improve flow between individual scenes
add in a plot twist?
finish chapters in the middle on cliffhangers
The bolded items are ones that I have given some attention to already (although no one has read since I have started working on #3.). #s 5 and 6 would require more structural change and I haven't gone there yet.
Currently, more practiced beta readers are reading, and perhaps they'll have concrete suggestions - we'll see.
My question: How does one perk up the slow parts of a novel, particularly beyond the list above?
(i.e. what might my blind spots be. I am leery of adding a plot twist or cliffhangers, because the story arc is right. But maybe these tools are so powerful that I should reconsider.)
Added as edit: (this may be better as a new question, except it is not really a question.)
My story is 230 pages.
I've mapped the arcs of the 2 (alternating POV) protagonists. The girl has a classic 3-act structure (or at least can be shoehorned into it fairly painlessly. Act 1 is in the first 60 pages, Act 2 is pages 62 - 160, Act 3 is pages 161 - 230 (but climax is last ~20 pages I guess.)
The boy doesn't fit easily into this structure - He has a point of no return on page 4, another on page 12, another on page 25, and so on. And with this in mind, he resolves to leave on page 5, realizes there is no going back on page 13, decides that onwards really is better anyway on page 26, and so on. As far as the act 2/act 3 division, it is the same gradual thing.
He is basically running from his problems, and the further he gets the more he realizes it isn't 'working.' He has a clear emotional break on page 127 and so his act 3 arguably begins earlier than the girl's (she is actually a resolving force for him up to page 160.) But he doesn't know the form of his resolution until page ~180.
This is why the 'contract' nature of the story has been a challenge for him.
However - I think his journey is more 'real' to life. We don't just flip a switch and enter a new act. We find our way. So I don't want to sharpen the focus of those breaks unless I need to.
Since no one suggested that I do that, in particular, anyway, I'm not going to worry about it. The problems are around and preceding page 140, which is in act 2 for the most part since the boy isn't firmly into act 3 until page 180.