High Quality Content by WIKIPEDIA articles! "Two Daughters" is the second episode of the third season of the American television show Numb3rs. The second half of a two-episode storyline, the episode features the aftermath of a Federal Bureau of Investigation (FBI) Special Agent`s abduction, which results in the search for not only the agent and her kidnapper but also for the true motive of the spree killings in the previous episode. As a character development, one FBI Special Agent`s actions during the case created a story arc for that character for season three. Series writer Ken Sanzel used the trawler problem, a real-life application used to find traveling boats, as inspiration for the mathematics included in the episode.