put a call into then local sheriff ron bruce. >> we had gotten a report of a drowning up on cottonwood creek. and they said they'd keep me advised. >> reporter: by then a group of medical responders made their way up to the creek to help. but still, no heartbeat. not a breath from leslie. and it was clear she was gone. >> we were not going to be able to bring miss mueller back. >> reporter: at the cabin alex was wondering why his parents weren't back yet. their hike was only supposed to last an hour or so. but they'd been gone more than three hours. >> were you worried? >> not really worried as in something happened to them. just more like it's kind of weird that they would stay out past dark if they're going tore a hike. >> reporter: it was past 8:00 p.m. when his dad got home. without his mom. >> it's my dad and the deputy. and yeah, they come in. it's kind of a shock to see, you know, when you're expecting somebody, to see strangers coming in instead. >> reporter: what do you think when you see that? >> not a whole lot of time to think, honestly. you kind of go into shutdown mode. >> repo

seasons change, waters rise and fall, and some believe the secrets of cottonwood creek will remain a mystery forever. >>> this sunday, what kind of president will joe biden be? >> faith in our institutions held, the integrity of our elections remains intact. >> we take a look at what joe biden has said through the years and on the campaign trail, on foreign policy. >> someone said to me in another interview, do you want to own afghanistan? i said, no, but we've got to rent it for a little while here. >> domestic policy. >> we've always moved forward as a nation when the middle class grows. when they grow, the poor have access and the wealthy get wealthier. >> and on governing a divided america. >> when we beat donald trump, you're going to see a great impediment taken out of the way. >> our look back and ahead at the man who's been running for decades. >> i announce my candidacy for president of the united states of america. [ cheers and applause ] >> are you running for president? >> i am running for president. >> you don't want to become president? >> i didn't say that. >> also, sa