It's Not Easy Being Mean
I feel like such a creep. I just wasted a character I've really grown to love, a character I have no doubt that readers will adore, too. I'd planned this character's demise from the outset, written it into the synopsis and plotted a good deal of the book around it, from events that propel the story forward to the character arc that will bring the protagonist to full fruition.
I still want to take it back. I thought about it long and hard, but no other event would equal this death's impact. You can't just march in a stranger, snuff 'im, and expect the reader to experience any real emotion. Instead, you have to develop the "victim" as you would any other character. Otherwise you end up with a Star Trek-style Red Shirt, one everyone can guess is doomed from the outset.
Writers don't (or shouldn't) randomly wax characters just because things are feeling a bit boring. We put a lot of thought, a lot of love (believe it or not) into the decision. We do it because death is a universal part of all our stories, as living beings on this planet, and without its shadow falling over our existence, even a fictional life rings false and empty.