In the twenty years since the discovery of high-temperature (Tc) superconductors, scientists have been trying to understand the mechanism by which electrons pair up and move coherently to carry electrical current with no resistance. “We are still at the beginning,” says Tonica Valla, a physicist at the U.S. Department of Energy’s Brookhaven National Laboratory, who will give a talk on his group’s latest results at the American Physical Society meeting in Baltimore, Maryland on Thursday, March 16, 2006. “If anything,” he adds, “it looks like the story is getting more complicated.”