N. Riley Heagerty’s Portraits from Beyond tells the fascinating story of Elizabeth and May Bangs, who were among the most prominent American physical mediums of the late 19th and early 20th centuries. They are most famous today for their ability to make full-color portraits of the dead appear on blank canvases, a phenomenon called “precipitated spirit painting.” All of this was possible at a time when mediums were able to develop to an extent that modern distractions seem to make almost impossible now.