One of the bests mysteries I have ever read was probably Series of Unfortunate Events: The Bad Beginning. The author Lemony Snicket made it to where after every chapter you would want to keep reading and you would always be at the edge of your seat. I just loved this story, because you never knew what was going to happen after.
Johnny runs out of the room. Sara follows. She is following Johnny to figure out what is going to happen to their relationship, but when she turns the cornera creature pops out and drags her against the floor of the hotel. While she is being dragged on the floor she yells "Johnny help me! Johnny!" Johnny hears her cries and starts running in the direction he heard them. But, when he turns the exact same corner she did he gets dragged against the hotel floor, too. He tires fighting back but the creature's grip gets tighter and tighter. Finally, he is knocked unconscious by hitting his head on some stairs. When he finally reaches consciousness he finds himself in a medal chair next to Sara in a dark room regretting what he said.