Castiel (more commonly known as Cas) is Dean Winchester's guardian angel. He helps Dean make some right decisions. He helps Dean go through painful moments and memories. But most importantly, he saves Dean. One evening, God allows all guardian angels to be humans for one month to allow them to change their host's lives for the better and to be allowed to get to know them better. But what happens when Cas falls for Dean? Especially when the clock is ticking?