You've done your first read through and find yourself bored in the middle. If you're bored, your readers will be too. What can you do? Here are some great ways to ratchet up your middle to carry the reader through to the end. (Resource: Revision and Self-Editing by James Scott Bell
1) Strengthen Your Opposition
What gets you to turn the page? For me, it's my concern for the protagonist. How is he/she going to prevail? This is accomplished by having an opposition powerful enough to really mess up your main character. If your opposition character isn't powerful enough it's going to be hard to convince the reader to keep reading. That said, be sure not to make your opposition so strong that he becomes unbelievable or stereotypical. An opposition character needs to be complex enough to show layers. The why of his evil deeds.
2)Add a Subplot
Romantic: Love interests always complicate things for a lead character.
Plot complication: Another plotline comes in to mess up your leads quest.
Thematic: This not only deepens the theme of the novel but usually requires the lead to grow or learn.
3) Raise The Stakes
Plot: Brainstorm new events that could bring in more trouble for your characters.
Character: If your character doesn't find himself in a delimma chances are you have a sagging middle.
Societal: Is there some larger issue that involves the community? Try upping the ante so that your lead has to consider the needs of the society in which he/she lives.
This is what I'll be looking at this weekend. Where are you in your revision process?