Explore the Secrets of Mystic Tower

It's a fiction fantasу book. Some kind funny and nice style. There should be a water tower where people could live for a while so there should be a place for them. And I have two main characters. First one is a killer, second one is a girl. The killer is a kinda teacher for her, no romantics. I want them to be like silhouettes - No hats, no river, no buildings.. The water tower is in the forrest. Colors - more like dark blue and dark green.