There is shock, anger and mourning in Spain after the second fatal train crash this year. At least 68 people have died in what is now the deadliest collision there in more than a decade. William Brangham reports.

Brazil is not the only country to have had dramatic election results this weekend. In Serbia, longtime leader Aleksandar Vucic lost a historic election that brought down his government. William Brangham discussed the results with Heather Conley.

When actor Christina Applegate revealed that she had been misdiagnosed with multiple sclerosis, it triggered not only an outpouring of empathy for her, but raised important questions about how often people are told they have the condition when they don't. William Brangham discussed why MS can be so difficult to diagnose with Dr. Michael Kornberg of Johns Hopkins University.

California officials are calling for an investigation into the actions of federal immigration officers after they allegedly injured and detained a U.S. citizen. Ricardo Gonzalez's detainment comes as an investigation by ProPublica found that more than 500 citizens have been caught up in the administration's immigration operations. William Brangham discussed more with ProPublica's Nicole Foy.

At a rally in Kansas on Monday, President Trump looked to boost Republican Sen. Roger Marshall in his reelection bid. Marshall faces a surprisingly close race with his Democratic challenger, Pastor Adam Hamilton. William Brangham discusses the Senate race with Jared Cerullo of PBS Kansas, the host of the weekly current affairs show, "Kansas Week."