>> reporter: mischele's mother had even called the police before mischele resurfaced.e now a missing person. >> yeah. she reported me missing. >> reporter: turns out the pressures of undercover work had finally gotten to mischele, and she'd taken a much-needed mental health day off by herself. >> so i went home first, and apologized profusely to my mom. then, i went to the police station, and they said, "okay, what's going on?" >> reporter: she told them about her year of spiraling down into this enigmatic man's strange world, of discovering his lies, of her undercover hunt for the truth. police launched a criminal investigation of their own. and then, they made their move. mischele was the bait. >> i said, this is where i'm going to be, and this is the route i think he takes. catch him. >> reporter: then she set up a date with jordan to run some errands, telling him she'd pick him up in town. >> i got there about two minutes before our meeting time. and for once, he was on time. >> reporter: she rolled down the window to hear him say he had to pop into the pharmacy, b

which is why mischel teamed up with sesame street workshop... >> me want it. but me wait. >> reporter: on a series of videos starring their guru of gluttony, to teach tots how to delay gratification. >> me can talk to self, me can stand up straight, me can take deep breath, me can self regulate! me wait. >> reporter: but it's never too late to self-regulate, mischel thinks. and so in the past few years, his ideas have inspired schools like kipp, a nationwide chain of public charter schools, serving low-income students, pushing high academic achievement. >> this time we're going to try to make a goal that's very far away. right? we're going to try to make a goal around your report card. >> reporter: of course, older kids have self-control issues beyond cookies and marshmallows. >> you are going to come up with everything that could possibly go wrong. >> joshua? >> talking to my partner. >> but you have to meet your goal. what are you going to do? >> i'm gonna pretend like they're invisible and i can't see them. >> use your imagination, i love it! brendaly, can