This story is part of an ongoing series on how China is reshaping our world. Science is one of the last bastions of globalization in times of heightened geopolitical tensions. Last year, despite a bitter trade war, China and the US collaborated on science with each other more than they did with any other country in the world. Scientists from both countries have built on each others’ efforts to tackle problems from climate change to cancer treatment to the race to find a cure for Covid-19, the disease caused by the novel coronavirus. But scientists in the US, especially those of Chinese descent, say they worry that openness is threatened—specifically by the FBI’s recent aggressive efforts to investigate researchers with China ties at universities and institutions across the country. The FBI’s increased scrutiny is partly a response to the legitimate threat of economic espionage for China, involving the theft of trade secrets and proprietary research intended to benefit Chinese companies and the Chinese government. Under the Trump administration, the scope of the effort has widened. In 2018, the FBI began partnering with the National Institute of Health (NIH) to target researchers with ties to China. A lot of these investigations uncovered violations of grant and university guidelines that didn’t rise to the level of espionage. But the investigations have led to a number of firings and resignations of researchers across the country. Some Chinese American scientists we talked to say the investigations have created a climate of fear, and discourage ongoing, above board scientific collaborations with China. Quartz traveled to Houston, Texas to find out how a recent FBI-NIH investigation affected the research community there, and why it raised questions of racial profiling. It’s the first episode of the latest season of our video series, Because China.