NEUROSCIENCE30 Memory’s Intricate WebA technical revolution provides insight into how the brain links memories, a process critical in shaping a picture of the world around us. By Alcino J. SilvaCOSMOLOGY38 Black Holes from the Beginning of Time A hidden population of black holes born less than one second after the big bang could solve the mystery of dark matter. By Juan García-Bellido and Sébastien ClesseMEDICINE60 Operation: DiabetesSurgery that shortens intestines gets rid of the illness, and new evidence shows that the gut—not simply insulin—may be responsible. By Francesco RubinoBIOLOGY66 The Evolution of DanceIs the unique human capacity for dance a fringe benefit of our upright posture and large brain, or did its social benefits help our ancestors survive thousands of years ago? By Thea Singer