Steins;gate (dub) Episode 7 -

It is revealed that SERN uses a secret network of IBN 5100 computers to encrypt their time-travel data. This makes Okabe’s search for the rare PC even more critical.

The world changes instantly. In this new worldline, the lottery experiment never happened, and Daru has no memory of sending the text. However, Okabe finds a scrap of paper in Luka's pocket showing that while Luka did receive the numbers, Okabe’s own poor handwriting caused Luka to buy the wrong ticket. The Warning from John Titor Steins;Gate (Dub) Episode 7

Shaken by his friends' lack of memory, Okabe contacts the online time-traveler . Titor explains the mechanics of their situation: It is revealed that SERN uses a secret