Sector 5 Reactor The Sector 5 Reactor is one of the eight Mako Reactor s built by the Shinra Electric Power Company to power the metropolis of Midgar in " Final Fantasy VII " . In the original " Final Fantasy VII " its layout is exactly the same as the Sector 1 Reactor ' s . Story . " Crisis Core - Final Fantasy VII - " . Zack Fair and his fellow SOLDIER First Class , Sephiroth , enter the reactor in search of the rogues , Genesis Rhapsodos and Dr Hollander . They fight Sahagin - like monsters , but with a strange mutation : they have the face of their missing friend , Angeal Hewley . Further investigation discovers both Angeal and Genesis were parts of Project G , an experiment performed by Hollander to make a modern Ancient . The experiment was a failure and Genesis had begun to slowly degrade , and could make copies of himself on human s . Hollander and Genesis arrive , and while Sephiroth deals with his old friend , Zack chases after Hollander until they reach the bottom of the plate . When Zack has Hollander cornered , Angeal arrives and shows Zack he is a monster by sprouting a white wing , then attacks . Zack refuses to fight his old friend , but the ground beneath Zack breaks from Angeal ' s attack , and Zack falls into the slums below . " Final Fantasy VII " . Following their successful attack on the Sector 1 Reactor , the members of the eco - terrorist organization AVALANCHE hope to repeat their victory on the No . 5 Reactor . After climbing through the city ' s underground subway system they break into the reactor . AVALANCHE fights its way down to the main generator and plant the explosives . On their way out , President Shinra greets the insurgents ; Shinra had known of the attack beforehand , and prepared the reactor as a trap for AVALANCHE . The robot Air Buster is sent in to defeat the terrorists , while President Shinra leaves , certain of victory . The party destroy the Air Buster and as it explodes , Cloud Strife is caught in the blast and falls into the slums below like Zack had done seven years earlier . Although the reactor explodes , it is later seen in use powering the Sister Ray cannon , indicating Shinra repaired the damage , unlike the Sector 1 Reactor , which was utterly destroyed and never repaired . This is odd , given that Jessie said she would make her next bomb even more powerful than the one that destroyed the Sector 1 Reactor , but is supported by the visibly smaller explosion that results . Given that Shinra had enough foreknowledge to set an ambush , it ' s possible the explosion was mitigated by them in some way . Locations . Main Staircase . The Main Staircase is accessed from Sector 4 - Exit . Here , the party can descend down the flights of stairs to access the upper piping . As the Sector 5 Reactor was not entered through the entrance like the Sector 1 Reactor was , this is the first area the party visits . Upper Piping . The Upper Piping is a small room in which the party can move across the top , before hopping onto the pipe and climbing down to descend into the lower piping . It contains ladders and what appear to be large steam pipes . Lower Piping . Accessed from Upper Ping , the Lower Piping similarly contains ladders and steam pipes . The party must traverse down in order to reach the core . Core . The core contains a large , piped , electrical machine with a valve at the bottom , and consists only of a small walkway towards it . Once the party accesses the valve , a cutscene initiates , and a bomb is planted to be detonated remotely , and there is no timer similar to the Sector 1 Reactor . Elevator . When accessed , the elevator only contains a small space , with a button to press for it to ascend up to the entrance . Entrance . The Entrance leads to Sector 5 - Outside Reactor , and has a much more light - brownish , metallic look . This area is accessed last , after the party retraces their steps through the reactor to exit . The door unlock minigame is required to leave . Quests . Destroying the reactor . The Sector 5 Reactor is entered through the underground subways , and the party arrives in the room with the main staircase . From here , the player must descend down to the Core , fighting random encounter s along the way , where a cutscene will initiate and AVALANCHE plants the bomb . After this , the player must then ascend back up to the main staircase by retracing their steps and entering through the door at the very top of the room to the elevator , which will take them up to the entrance of the Reactor where they will leave . A minigame is required to unlock the door , and the party will then leave the reactor , but must fight Air Buster on the way out . Door unlock minigame . In order to leave the Reactor , the party must leave through its entrance , which is blocked off at the end by a gate that can be opened only through a terminal in a room to the left of it . Cloud , Tifa and Barret must all press the button simultaneously in order to open it . The player controls Cloud , and must press the button ( using on PlayStation , [ OK ] on PC , on PlayStation 4 ) closely in time with the others . The other two will press the button approximately two seconds after Tifa announces it , which the player must time . Date mechanics . The game has a hidden affection value that determines whom Cloud will go on a date with in Gold Saucer later . The value is determined by the dialogue and party member choices made prior to the date . Cloud is barely hanging on after the explosion : Musical themes . Throughout the reactor , the background music is " Mako Reactor " . In " Crisis Core - Final Fantasy VII - " " The Skyscraper of Iron and Steel " plays , and later " Combat " when chasing Hollander . Other appearances . " Final Fantasy Record Keeper " . Mako Reactor No . 5 is unlocked by completing Mako Reactor No . 1 in the " Final Fantasy VII " realm . Completion of this dungeon unlocks Mist Cave in the " Final Fantasy IV " realm , Zanarkand in the " Final Fantasy X " realm , and Sastasha Seagrot in the " Final Fantasy XIV " realm .