Stand-alone - it's not DLC, it's a full game - starring Chloe Frazer, and Awesome Lady from Uncharted 4, Nadine Ross! Very cool, very cool.
"From the critically acclaimed developer, Naughty Dog, comes the first standalone adventure in Uncharted franchise history led by fan-favorite character, Chloe Frazer.
In order to recover a fabled ancient Indian artifact and keep it out of the hands of a ruthless war profiteer, Chloe Frazer must enlist the aid of renowned mercenary Nadine Ross (from Uncharted 4: A Thief's End). Together, they’ll venture deep into the mountains of India in search of the legendary artifact. Along the way, they’ll learn to work together to unearth the mystery of the artifact, fight their way through fierce opposition, and prevent the region from falling into chaos."