REACHING CRITICAL MASS IN WRITING A THRILLER

 I have reached the point in my novel, The 9 Monkeys, where I have to decide exactly how I bring all the subplots back in line with the main plot. I have several subs with interesting characters that I have come to really like. Unfortunately, a couple of them have to go...as in dead-go. My main man ,John Locke, wouldn't hesitate in getting rid of all of them, they are mutts that need killing, and have relentlessly chased John for days, wanting desperately to know what he knows about the Monkey House in Saigon. It's a tough decision that has to be made before I can go any farther with the story.
What do other writers do when they become attached to co-stars or B-part players. The old marketing term may apply here, " You have to be willing to eat your young."