Episode: Steins;Gate - 9 - Chaos Theory Homeostasis - II 106453

As Faris learns about the PhoneWave upon overhearing a discussion between Rintaro and Daru, Rintaro discovers that the IBN has gone missing from the lab, which was apparently never found in the first place as a result of Moeka's D-Mail. Kurisu deduces that the minor changes to the past that resulted from their previous D-Mails has caused a butterfly effect, leading to changes beyond their control. After learning that the IBN 5100 had been previously taken from Ruka's shrine, Rintaro finds Moeka in town and confronts her, only to learn that she does not know the whereabouts of the IBN either. Rintaro also discovers that, unlike the previous World Line, everyone has met Moeka before in the current one, giving creedence to Kurisu's theory. Rintaro and the others later visit Faris, whose true identity is revealed to be Akiha Rumiho, whose family owns Akihabara. Faris offers them information on the IBN 5100 in exchange for being allowed to send a D-Mail ten years into the past. Rintaro reluctantly agrees and allows her to send the D-Mail, causing him to experience another World Line shift. After learning from Faris's father that they no longer have the IBN 5100 in their possession, Rintaro discovers that the physical geography of Akihabara has completely changed, no longer being a mecca for anime culture.

Source: Wikipedia