Whenever a group of people work together toward a common goal, they ultimately discover that there seem to be both hills and valleys along the road to success. Take for example a sports team. Yes, good teams win games, they also lose some, but the overall picture is one of winning, setting new records. Then there's what seems to be a sudden change of direction. One game is lost, then another.
Morale starts to sag, team work begins to be replaced with blaming and faultfinding.
Or perhaps it may be a business enterprise. Everything goes well for the first several years - increased sales and profits, and before you know it, the company is going public and trading stock on the Dow Jones. Then, with apparently little notice, the course suddenly changes. Perhaps one of the founding partner retires, or there's a change in the market. Sales begin to drop, morale droops, and fears that the company might go under begin to be whispered by even the most loyal employees.