A new play in Chicago turns Boston Cardinal Bernard Law’s testimony about the priest sexual abuse case into drama. “Part of the power of ‘Sin’ comes from its being strictly documentary. Michael Murphy, a playwright who lives in California, distilled it from the 11,000 pages of Cardinal Law’s depositions and from hundreds of newspaper articles. He took some dramatic liberties, like condensing the dozen lawyers who questioned Cardinal Law into just two, but did not add any dialogue.”