The secrets of the walls

On the two banks of the river, the city spread.
It is not only inhabited by people. Living statues roam the streets, bronze birds spread news, a golden angel is indifferently observing from the top of the cathedral.
Among the walls of the city there are five hiding places.
Everyone hides a key that gives the owner special forces. With their help, you can destroy buildings, change the weather and even wrap the flow of the river back.
Life went on as usual until the first key was abducted. Now I need to have time to save the rest, and also find answers to many questions. What do the statues want? Where are the keepers hiding? And how to save
reason when the usual world flies into the abyss?