♪ ♪ this is "nightline." >> tonight, deadly treasure. >> it's the thrill of the chase. >> adventurers scouring the rocky mountains for a chest said to be filled with millions in riches. >> oh my god, i see bronze. >> hidden by an eccentric antiques dealer. their only guide, a cryptic poem. >> begin it where warm waters halt and take it in the canyon down. >> it's not just riddles and rhyme. some searchers dieing on the treasure trail. killer kim? the plot allegedly orchestrated by north korean dictator kim jong-un to assassinate his own half brother. >> it was planned. it was executed in a professional way. >> did his spies trick two strangers into committing a murder by convincing them they

were part of a prank tv show? and praise from an unlikely american friend. >> to me he's not a bad man. >> but first the "nightline 5." >> my hygienist told me to try a mouthwash. i tried crest. it does more than give me fresh breath. >> provides all of these benefits to help you get better dental checkups. go pro with crest mouthwash. >> checkup? nailed it. i tried hard to quit smoking. when we brought our daughter home? that was it. now i have nicoderm cq. >> the patch with extended release technology helps prevent your urge to smoke all day. >> best thing that ever happened to me. every great why needs a great how. >> number one in just 60 seconds.

♪ ♪ there are two types of people in the world. those who fear the future... and those who embrace it. the future is for the unafraid. ♪ all because of you ♪ ♪

good evening. thanks for joining us. tonight one of the biggest mega millions winners in history coming forward. at just 20 years old, floridian shane missler taking home a cool $281 million. everyone has the dream of winning the big prize, right? across the country in the rocky mountains we'll meet people on an actual treasure hunt. risking their lives and braving potential bear attacks to find their big prize. how far would you go? here's abc's clayton sandell. >> reporter: somewhere in the vast rocky mountain west, near a stream in a forest, or at the edge of a meadow, people are hunting. >> wait. he could have stashed it under this end. >> reporter: for a legendary supposedly hidden treasure worth millions to whoever finds it first. >> let's go this way. oh my god! i see bronze! >> reporter: dale nightel and cynthia mechum among perhaps thousands looking for this bronze chest, said to be filled

with a bounty of gold and rare artifacts. but only one man says he knows where it is. >> here's a wonderful artifact. this is a lantern. see the wick? >> reporter: forrest fen is an 87-year-old former military pilot turned wealthy antiques dealer. he claims in 2010 he hid the treasure somewhere in the rocky mountains. why would you do that? >> well, in 1988 i was diagnosed with what everybody thought was terminal cancer. decides that, we were going into a recession. and i just wanted to give some people hope. >> reporter: fen's health recovered. >> going inside the vault here. >> reporter: the idea of creating a modern-day treasure hunt stuck with him. >> there's 265 american gold eagles and double eagles. there's ancient middle eastern gold coins. there's hundreds and hundreds of gold nuggets. two of them as big as a hen's egg. >> reporter: he says even he doesn't know what it's all worth. >> writers have appraised it

between $1 million and $5 million. >> reporter: he estimates around 350,000 people have taken up the search. he says, to find the treasure -- >> begin it where warm waters halt and take it in the canyon down. >> reporter: all you have to do is solve nine clues in his cryptic poem. >> not far but too far to walk. put in below the home of brown -- >> reporter: the treasure could be hidden anywhere, in literally tens of thousands of square miles of territory. anywhere from new mexico to here in montana. that, of course, assumes it exists at all. some say it's a hoax. >> the story is real. the treasure is real. the treasure is hidden where i put it. >> can you take me out there and show it? >> no. >> it might not even be here in new mexico. >> reporter: today, thousands of online forums, videos, and documentaries like "the lure" fuel speculation as endless as the landscape. obsessing over fen's every word for the tiniest clue. >> there will be no paddle up

your creek -- >> i get between 100, 120 e-mails a day. >> reporter: there's even the occasional death threat. >> there's one guy called me, he said, tell me where the treasure is right now or i'm going to kill you. >> reporter: so far, nobody has found it, including dale, who runs a website dedicated to finding the treasure. how many trips have both of you made trying to crack this one? >> it's somewhere in excess of 65 different trips. >> i've made over 100 trips. >> reporter: but this time dale and cynthia are convinced the first clue -- >> begin it where warm waters halt -- >> reporter: leads to the yellowstone national park area, known for steaming hot geysers and pools. >> we're going to start where warm waters halt. and for us that's madison junction. >> reporter: it's all a place forrest says he spent many summers as a kid. >> and i really believe it's at a place that has sentimental value to him. >> reporter: in september, dale and cynthia each drove hundreds of miles to check out their latest hunch, inviting

"nightline" along. when you find the treasure, how are you going to divide it up? are we talking thirds-ies here? >> how about your crew? exclude them, never mind, sorry. >> fifths, whatever. >> where have you brought us this morning? >> this is greeling creek. >> reporter: into the wilderness we go, looking for something the poem calls a blaze. >> if you've been wise and found the blaze, look quickly down, your quest to cease. >> i don't know what a blaze is. >> neither do we. something in the terrain, a big white rock, a white stone, a cliff, maybe even a mound of rocks. >> reporter: but just a few minutes later -- >> to me, that's the blaze. >> reporter: they say they've found it. >> look quickly down. >> quest to cease, but tarry scant with marble gaze -- >> what does that mean? >> it means, get your butt over there and start looking quickly down off that rock blaze. and find the hidy spot.

>> reporter: as we venture deeper into the wild, we're not alone. >> oh my god, there's a dead animal. it's a dead deer. >> that tells you there's a bear in the neighborhood? who brought the bear spray? >> i do have some bear spray. >> reporter: the potential for danger, bears included, is real. and recently people have been literally dying to find fen's treasure. in june, paris wallace, a colorado pastor, found dead in new mexico. his wife says they like to search together, but the last time he went alone. >> it was a great way for us to get out in nature, to have some quality time together. >> reporter: in 2016, randy bellu's body was found along the rio grande river. he'd vanished six months earlier, his family says while treasure hunting. 31-year-old eric ashby went missing in colorado. his friends say he was searching for fen's treasure too. fen was in his 80s when he hid the treasure somewhere out here in the wilderness. he says he didn't put it

anywhere dangerous. still, there may be those who are taking too many risks to try and find it. that's why new mexico's top cop has asked for fen to call the treasure hunt off. >> you had talked about giving more clues. again, i call for you to pull it. >> i'm not going to give a clue help people find the treasure, i'm going to give a clue to try to keep them out of trouble. i didn't anticipate people would die searching for my treasure. in the back of my mind, it had to be logical that that could happen. grizzly bears alone are something to think about. >> it weighs on you? >> a little bit, you know. i don't feel responsible, i don't feel like i'm to blame for any of those things that happened. >> reporter: back with dale and cynthia. >> you see the big boulders over there on the ground? let's see if there's any kind of a place he could have shoved that chest in underneath that.

>> reporter: no rock is left unexplored. >> this is even better. but it's not there. >> reporter: there is no gold. but just as fen says he intended, the quest comes with other rewards. >> it's an adventure to go looking. >> even if i was searching the same area maybe a dozen times, every day was a new start. >> it's definitely going to be found. somebody's going to figure it out. >> reporter: fen says some treasure hunters have gotten tantalizingly close. >> 200 feet. i know exactly where they were. because they told me. >> that's close. >> not close enough. >> reporter: fen says this may be his last tv interview. >> i just don't feel like i have anything to say anymore. >> reporter: so we had to ask. is there any tiny little hint, any tiny little clue you'd like to leave us with? he's thinking about it. >> no. >> okay. >> well, i will give you a clue. try to simplify, if you can. that's good advice.

>> have you secretly given us clues in this interview that we should go back and parse your words? >> i've said more than i should have said. >> reporter: for "nightline," i'm clayton sandell in albuquerque. up next, how kim jong-un seized power in north korea after his brothers fell out of favor. and how he allegedly had one of them killed. ( ♪ ) with 33 individual vertebrae and 640 muscles in the human body, no two of us are alike. life made more effortless through adaptability. the perfect position seat in the lincoln continental. ( ♪ )

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we all know north korean leader kim jong-un now holds a tight grip on power. but this iron-fisted ruler was

not the son expected to assume power when his father died. tonight abc's bob woodruff has the fascinating story of how he rose in the ranks because of hin ways. >> reporter: inside the largest and busiest airport in malaysia, a murder is about to happen. >> you could not have had a crazier story. >> reporter: watch as airport surveillance cameras capture the scene. a middle-aged man checking his flight information. no idea he is about to die. >> it was planned. it was executed in a professional way. >> reporter: why target him? because he's actually north korean royalty. kim jong-nam, half brother to the most enigmatic leader in the world, kim jong-un. >> some people believe that kim jong-un perceived him as a rival. >> reporter: think of it as east asia's version of "game of thrones." the sacred family tree of the kim dynasty starts with kim

il-sung, north korea's founder, their great leader. his offspring kim jong-il, esteemed as the dear leader, known for his bizarre haircut and penchant for jumpsuits and platform shoes. it's the third generation of the blood line where three young brothers first appear. it is the ldest,kim ong-nam, who is destined to one day lead. >> kim jong-nam's mother was the first and real wife of kim jong-il. anybody who comes after is kind of a mistress. >> reporter: in fact, it is a mistress who gives birth to the current north korean leader, kim jong-un, as well as another son named jong-cho. it was a matter of time, experts said, before kim jong-nam would one day be the natural heir to the family dynasty. but then he blew it. in 2001, kim jong-nam was caught at an airport in tokyo trying to enter with a fake passport to visit tokyo disneyland.

>> japan is one of the enemy countries of north korea. this was of huge embarrassment to the regime. >> reporter: jong-cho would also be undone with fixation of western culture, namely the music of eric clapton. >> he doesn't have the right temperament and characteristics, that's what his father thought. >> reporter: that leaves the path clear for the youngest son, kim jong-un. >> he had a little bit of a tough streak in him. and that's what his father liked, that he was strong. >> reporter: december 2011. north korea says good-bye to the dear leader, kim jong-un. as 27-year-old kim jong-un assumes the leadership of his country. >> i don't think we know too much about this person that's the leader of north korea right now. >> reporter: the only american known to have become close to kim after he assumes power, the flannel buoyant former nba star and chicago bull dennis rodman. his latest attempt to get into north korea was sponsored by a company called popcoin.

rodman makes no apologies for his embrace of a dictator. >> as a friendship hug, you know, even though they say he's a bad man, to me he's not a bad man. >> reporter: even in exile, kim jong-nam was criticizing his brother's rule. >> kim jong-nam said to me, north korea should be reformed. it's a message to kim jong-un. >> according to some people i talked to in macao, he knew that his brother was after him. >> reporter: then it is february 13th, 2017. and here's kim about to walk right into the arms of his alleged assassins. in this surveillance footage obtained by fuji tv. he studies the departure board, oblivious to the plot later exposed by malaysian authorities. a death squad of north korean spies and two young women recruited to kill him. >> it was an incredibly elaborate plot. it took months, maybe even years, to set up. >> reporter: the story, as

malaysian police and prosecutors later reveal it, involves 28-year-old donti yuan from vietnam and ayesha from indonesia. weeks before the hit recruited outside this kuala lumpur nightclub by a man who appears briefly in a video she later posted on facebook. >> when we go -- >> reporter: he and his colleagues claim to be producers. auditioning the women for a hidden camera tv show. >> like "america's funniest home videos." they were told they'd be filmed while putting various substances on the faces of strangers. >> reporter: clark says the women did not know each other. he says the producers keep them separate as they rehearse the in your face prank in high-end malls and hotels around kuala lumpur and elsewhere. >> they even took it to the airport, they had her do dry runs there. >> reporter: the money is good. at least $100 per prank. but there is no tv show. authorities say the producers

are north korean agents with murder in mind. the day of the final act, a security camera captured one of the women in a coffee shop accepting money from a man with a selfie stick, ready to pull off the final prank. she and the other woman swoop in from separate directions. >> the indonesian woman who struck first wiped her hands across his face, stepped back, and then the second woman, the vietnamese woman, immediately wiped her hands across his face as well. >> reporter: this time the substance is not harmless. it is vx, one of the deadliest nerve agents known to man. >> if it's not counteracted almost immediately, you are going to die. >> reporter: kim approaches airport workers at an information desk. he is concerned enough to rudely interrupt the conversation to get their attention. clark points out this man at the edge of the frame on the security camera.

he says it's one of the north korean spies. >> the north koreans made sure that they had eyes on him every second. >> reporter: speaking with police, kim gestures to his face. >> reports of this moment say he wasn't really making much sense anymore, he was having trouble holding a coherent conversation. >> reporter: they escort kim to the airport medical clinic. by this time, the poison is already taking effect. causing every muscle to spasm. which does explain that suddenly stiff walk. >> this isn't sort of that healthy man we saw just moments ago. >> reporter: minutes later, kim dies in an ambulance. >> those spies immediately after the hit cleared passport control before the malaysian authorities had any idea what was going on, got on their flights, escaped the country. >> reporter: as for the two women -- >> they walk straight into the bathroom to wash their hands. >> malaysian prosecutors have said that this is evidence that the women knew what they were doing. the women's defense is that they had been told by their north

korean handlers that they should wash this substance off afterward. >> reporter: the women are arrested within two days. the trial of the female assassins who pled not guilty got started this summer. if convicted, they face execution by hanging. the north koreans continue to deny having a hand in the airport assassination. or even that the victim was indeed kim jong-nam. for "nightline," i'm bob woodruff. >> our thanks to bob woodruff. up next, the heartwarming speech from a pint-sized actress wise beyond her years. you won't believe how much is new at red lobster... ...that is, until you taste our new menu. discover more ways to enjoy seafood with new tasting plates small plates, with big flavor- like yucatan shrimp

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learn more at cancercenter.com/experts ♪ ♪ there are two types of people in the world. those who fear the future...

and those who embrace it. the future is for the unafraid. ♪ all because of you ♪ ♪

finally tonight, in "the florida project" brooklynn prince plays a 6-year-old growing up in a family struggling to make ends meet. after winning a critics choice award for best young actor, she

wowed the audience yet again. >> wow, this is such a big honor. but i would like all the nominees, you know, are great, you guys are awesome. we should go and get ice cream after this. now i'd like to dedicate the award to all the heroes out there. guys, this is a real problem. you need to go out there and help. thank you so much. >> you heard the lady, let's go get some ice cream and help some people. thanks for watching "nightline."