Prologue to the Beginning and End

Founder of an inventors group in Akihabara, the Future Gadget Lab (AKA The Lab), Okabe Rintarou, goes with another member of the group, his childhood friend Shiina Mayuri to a press conference held by Doctor Nakabachi at the Radio building. Okabe objects to the doctor's theories of time travel, but a girl appears and drags him away...