However, all that began to change five years ago when the skimmers first appeared. Fell creatures from the sky with an appetite for warm flesh and blood, the skimmers fly over The Wall in the warm season and attack anything they find out in the open. As they are attracted by light, sound and the smell of flesh summer nights see the citizens of Weld locking themselves up into their houses. Sitting in the dark, eating cold meals and carrying on conversations in whispers, they listen to the sound of leathery wings flying overhead. Even leaving a shutter over a window open a crack could be enough for the skimmers. Many a morning houses have been found cracked open like eggs and their inhabitants slaughtered.
As the attacks have grown fiercer and the measures taken by the Warden to protect the people have failed, disquiet begins to grown among Weld's citizens. Both Rye's older brothers, big burly brave Dirk and clever Sholto, the apprentice healer, have given voice to their frustration. So when the Warden calls for volunteers to leave Weld and search for the source of the Skimmers, it's no surprise that both end up leaving as they each in turn come of age. When they both fail to return Rye obsesses over their fate. For although the Warden declares them dead after they have each been gone a year, Rye believes they are both still alive.
When disaster strikes Rye and his mother, Skimmers destroy their only means of livelihood and they are forced to seek shelter in Warden's Keep, Rye's decision to lie about his age and volunteer to leave Weld is only inevitable. How, though, does one leave the city? For one of the oddities of Weld is there is no visible gate allowing exit or entrance. Hence the title of the series. Secreted well beneath the Keep lies a secret chamber containing three doors. Made of gold, silver and wood each of the doors leads to a different destination in the outer world.
While Rye's first instinct is to pick the wooden door, his quest isn't to find the skimmers like everybody else. No, he is determined to find his two brothers and bring them back alive. Knowing his brothers as well as he does he realizes brave Dirk will have chosen the door of gold and Sholto the silver. Determined to bring his older brother back he's just about to leave through the gold door when he's interrupted. A girl his age climbs out of the fireplace in the secret chamber and demands he take her with him. He only gives in when she threatens to tell the Warden he's underage. So Rye and his unwanted companion, Sonia, step through the gold door into another world.