Tennis's greatest players converge at the U.S. Open, where a new generation—Coco Gauff, Irina Sabalenka, Carlos Alcaraz—competes amid lingering legends like Serena Williams and Novak Djokovic. Matthew Futterman explores the rivalries, mental battles, and personal dramas defining the sport's most unpredictable Grand Slam. Serena Williams, at 44, returned to competitive tennis after two years, using GLP drugs to regain her body and playing mixed doubles with Carlos Alcaraz in a stunning comeback moment.