: and gwen ifill talks to human rights activist john prendergast and his "unlikely brother," michael mattocks, co-authors of a new book chronicling their unique bond. >> did you think who is this strange white guy taking me out in the street like this? >> in the beginning, yeah, but i really at that time didn't care because we was having so much fun. >> lehrer: that's all ahead on tonight's newshour. major funding for the pbs newshour has been provided by: >> well, the best companies are driven by new ideas. >> our future depends on new ideas. we spend billions on advanced technologies. >> it's all about investing in the future. >> we can find new energy-- more cleaner, safer and smarter. >> collaborating with the best in the field. >> chevron works with the smartest people at leading universities and tech companies. >> and yet, it's really basic. >> it's paying off every day. the william and flora hewlett foundation, working to solve social and environmental problems at home and around the world. and with the ongoing support of these institutions and foundations. and... this program was made