Definition: In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.
Input: Elle Greenaway:  Dominant one is the mastermind . That 's not to say that the submissive partner is in any way pure or innocent in this exchange .
Jason Gideon: If their criminal desire was n't present , their partnership would n't work .
Derek Morgan: The offenders share a common delusion . It 's _ one _ that you and I would never accept , but it 's this bond that justifies their actions .
Detective Robert Portillo: So we 're looking for two sick minds who complete each other .
Dr. Spencer Reid: It 's kind of like the perfect storm . Once these deviant personalities collide , they 're deadly and unstoppable .
Aaron "Hotch" Hotchner: Like the D.C. snipers or the Columbine assassins . Sometimes they 've met in childhood . Other times , they can be related , like the Hillside Stranglers , Angelo Buono and Kenneth Bianchi , psychopathic cousins who terrorized women in Los Angeles . The dominant partner makes the submissive one feel invincible . That 's his reward for doing as he 's told . Unfortunately , there are countless opportunities for these twisted minds to meet . And once they 've pulled off their vicious acts , the two accept this as common behavior and become bored with normal activity . They live only for their new reality . They 're obsessed with it , addicted to it . And there 's a fierce loyalty between the two . The submissive one , however , is usually less intelligent and easier to catch , and once caught , he is easier to turn .
Jason Gideon: Lack of remorse increases their aggressiveness . Sexual sadists will stop when they 're caught .

delusion