The conclusion of STEINS;GATE 0! Mayuri learns that her life was unknowingly saved thanks to Kurisu's sacrifice on another world line. Thus, in order to save Rintaro Okabe (or rather, in order to resurrect Hououin Kyouma) Mayuri decides to enact Operation Arclight... a time-travel mission to the past! The heroes of Steins;Gate return for a new time-altering story set in an alternate world where the Future Gadget Lab members failed in their original mission. Can one final chance lead to a happy ending?