Hello there, everybody. First time poster here. I've worked on my personal project for quite some time, and it's nearing completion, but one thing still confuses me: Do I have to explain every thing or every detail that could have some meaning as a background information of the plot? Something that is not vital in understanding the plot, but could shed light on relating events. For example: "He found a picture of two men, but did not know who they were." Or "I can't make any sense of the note. It just says 'beware of the blue pants'." Do I have to explain, at some point, who these men are or where is that picture coming from, or do I have to explain why someone would have to watch out for blue pants? If neither the men, the picture nor the pants are essential parts of the plot, but mostly just tools for setting the mood or teasing the reader. Is it bad writing if I leave the meaning of some details into obscurity, for the reader to guess or speculate at his/her will?