Cassie Drake taking the lead of her Father in a college trip where she's becoming a legal archeologist only to find her love interest being some douche bag daddy's boy secretly funding a private excavation right under the University's dig to get a lead to treasure. Being how we see Cassie is the kind who already stumbles into people's private stuff (ex: Drake's Cabinet) she could be one who sees the glory of finding things too. Though I see her more of "It belongs in a Museum"
type so could be interesting if she gets in heap of trouble with Drake coming to the dig site to find his daughter is missing. Which puts Drake right back where he thought "I'm too old for this ****" and him being more like Sully was in UC1 as the gameplay switches back and forth from Nathan to Cassie till you apprise the role of Cassie and now Nathan is the Sully AI. Also could be a way to bring back one last time with Chloe Frazer as either a hired hand for young douche bag dude or playing both sides being a slight backstabbing mentor for Cassie for a bit playing the "I knew your father and etc". And that would be Uncharted 5 in a nut shell for Naughty Dog. Simple and to the point.