. >> reporter: first devon horn, the 20-year-old hot shot from houston. is only one reason to beep here. are you going to win this thing? >> yes. that's the plan. >> reporter: that's the plan. but as we and devon would soon learn, it's not about winning or even surviving. okay, about surviving but about something much more. >> a test to everyone and their horses to finish happy and healthy. >> reporter: there is a lifelong equestrian. at 55 she is one of the oldest contestants and has a secret reason for attempting this race. >> reporter: you have something to fight. >> i have had something to fight. >> reporter: do you feel comfortable sharing it with us? >> i would rather share after it is over. how is senate -- how is that? >> reporter: and there is tom, a friendly 23-year-old college grad who recently entered the work force. >> call it a quarter life crisis. a risk management analyst. >> reporter: are you out here? did you not manage that correctly? >> one thing i have learned about risk you have got to take them when you can. >> reporter: but that ni

horn honking) over here! he went that way! emily: devon! devon, give that ball back. that's not your ball. okay. that's good running. (laughing) i don't know why you volunteer to come here. it's like lord of the flies. (phone chiming) all right, let me just make sure everything is cool. jewel heist? mad bomber on the loose? no, there's no crime. sherlock quizzes me sometimes. it's part of the work. quizzes you about what? dollhouse. cute. yeah, sherlock builds it. is that doll supposed to be dead? (laughs) it's a way to practice flash analysis of crime scenes. suicide by prescription meds? ha. who knew? so, are you getting any "real world" time? uh, this is... this is pretty much it. you know, as cool as it is, you spend your time chasing thieves and murderers. you live with your business partner. it might be a good idea to carve out some time for... you know, regular stuff. keep your options open. (phone chiming) wow. that's a whole family of dead dolls. yeah. it's ghastly. "no foul play." uh, keep my options open? what is that, what, about dating? okay, no, put that down. i know it's not your