when helene disappeared. it wasn't until 2019 that she accepted a challenge. >> i had to win. i wanted to win it for helene. helene pruszynski grew up as the baby daughter in a close knit family of five in hamilton, massachusetts. >> everybody that met her liked her company. >> janet was her older sister by nine years. but you didn't treat her as this annoying, younger sibling? you guys were -- >> not at all. she was my best buddy. she was a surprise, i think, through the family. and she just brought sunshine and life to our household. >> i met her my freshman year of high school. she was a sophomore. we both were part of a singing group called harmony and that's really where i got to know helene very well. >> she left to sink?