72 Hour Mode (Dead Rising 2)

72 Hour Mode is the name given to the main game mode of Dead Rising 2, for simplicity reasons, as it is not directly refered to as 72 Hour Mode in the game like it is in ''Dead Rising. ''The main game mode is actually around 96 hours storywise, as there is a full additional day in the game after the military arrive (provided certain requirements are fulfilled), but still before Overtime.

Following the case files, the mode will last about 8 and a half hours real time in which the player(s) are allowed to follow the storyline or completely ignore it. Ignoring it however, will cause the game to end upon the arrival of the military, making this route about 6 and a half hours long.

It is possible to get multiple endings to the story, one of which will unlock Overtime.

Story
Note: ''The following storyline details Ending S, accomplished by completing all case files during the course of gameplay, and omits non-vital plot points and any optional events the player is not required to participate in. ''

Five years after the Willamette Incident of Dead Rising, former motocross champion Chuck Greene takes part in Terror is Reality, a controversial American Gladiators-like game show where contestants kill gathered zombies in various ways for money, sport and fame. The show's latest incarnation, "TIR XVII: Payback", is currently held in Fortune City, an amusement and entertainment resort somewhere in Nevada, and based off the casino strip in Las Vegas, which was destroyed in a zombie outbreak three years ago. Tyrone King, or better known as TK, hosts the show with his twin assistants, Amber and Crystal Bailey. Chuck participates in the show for the purpose of raising funds to buy Zombrex for his daughter, Katey, who was bitten by her zombified mother in the previous outbreak.

After Chuck wins the prize money in the latest event, he retires to the backstage where he is trapped in an elevator after a mysterious explosion. Upon exiting the elevator, he finds that an outbreak has occurred in the city and many people are killed or changed into zombies. Finding Katey, Chuck takes his daughter to an emergency shelter where survivors have gathered.

Inside, Chuck is confronted by Sullivan, a Fortune City security guard and the only reserve man to make it into the shelter. Sullivan is reluctant to allow an infected person like Katey into the bunker, but Chuck convinces him to let them stay as long as he finds and gives her a daily supply of Zombrex until the military clean up and rescue arrives in three days. Chuck meets Stacey Forsythe, the leader of the Nevada branch of "Citizens for Undead Rights and Equality (CURE)". The CURE organization advocates zombie rights and demands that infected people be widely administered with Zombrex, which has been expensive.

During a news broadcast by Channel 6 Action News, Chuck discovers he has been framed as the perpetrator to the zombie outbreak in the city. Seeking to clear his name, he enlists the help of Stacey as well as the Channel 6 news reporter, Rebecca Chang, who was the one who reported the incriminating evidence. Meeting up with Rebecca, Chuck is unable to get the reporter to reveal her source who gave the evidence. Rebecca brings him to the central security room to watch the surveillance footage, but discovers that the guards inside are shot dead and all the equipment and footage destroyed, proving a cover-up is in progress.

Chuck returns to the Safe House to find that Sullivan has watched the news on Chuck being the perpetrator of the outbreak and demanded that he and his daughter be kicked out from the bunker. Chuck explains that he intends to search for clues to clear his name, and he will surrender to the authorities if he fails to find any evidence once the three days are up. Sullivan makes a deal with him to let him stay so long he continues rounding up survivors to the shelter. Stacey has monitored suspicious activity in the Underground Tunnels. Chuck enters the tunnels to find TK and a group of hired mercenaries moving unknown equipment on the maintenance train. Upon defeating the mercenaries, Chuck confronts TK and the TiR host admits to having set him up as the scapegoat. Before Chuck can question him further, TK manages to get away by unhooking his train car from Chuck's. Later, Stacey spots numerous mercenaries breaking into the casino vaults scattered around the city. She and Chuck deduce that TK is behind everything, and is using the outbreak to perform a heist. Chuck manages to foil TK's plans by killing TK's goons and destroying the power drills that were attempting to break into the vaults.

Rebecca decides to trust Chuck enough to bring him to meet her source of information inside a nightclub. When Chuck arrives, he realizes that the twin assistants Amber and Crystal are the source for the evidence incriminating him and have taken Rebecca hostage. After a fight in which one of the twins is killed and the other commits suicide, Chuck further confirms that TK is responsible for the outbreak and created phony evidence to have him take the fall.

Realizing his plans have come to naught, TK seeks to make his escape on a helicopter with his remaining loot. After a short fight, Chuck manages to bring down the chopper while TK is knocked out. Bringing TK back to the Safe House, Chuck and the others learn from him that Chuck was deliberately set up by him under orders from a mysterious group. However, TK refuses to divulge any more information. Chuck has TK handcuffed in the infirmary, with Sullivan standing guard while he and the others figure out what is really going on.

The three days period passes and the military troops enter the city to clean up and rescue survivors. However, the operation goes horribly wrong when the zombies mutate from a noxious green gas emanating from underground. Unable to react and defend themselves from a stronger and newer form of zombies, most of the soldiers are wiped out. Rebecca films the chaos but she ends up lost in the tunnels due to the thick gas covering the city. Heading into the underground tunnels, Chuck rescues Rebecca from the military commander of the operation, who has gone insane from the shock of losing his men and has taken her hostage.

Back in the Safe House Sullivan assures them that another rescue operation will be attempted, and if it fails, a firebombing would be ordered. Chuck decides they must somehow get the attention of the outside world that there are still survivors here. Chuck and the others discover on the news that the city has been reported to have no more survivors and the rescue troops wiped out. According to the news, the government plans to firebomb the entire city earlier than planned in a little less than a day. At this time, the Safe House is suddenly breached and zombies start to pour in. As survivors fight for their lives inside the bunker, Chuck gathers the necessary equipment to repair the shelter barricades. After the crisis is over, Chuck discovers that TK is missing and finds him bitten by a zombie while trying to escape in the confusion. Sullivan tells them he was knocked out by TK when he let his guard down. To make sure TK pays for his crimes, Chuck decides to administer Zombrex to him to keep from turning.

Trying to find the source of the gas, Chuck heads for the underground tunnels. He discovers that the normal and mutated zombies are all heading to a closed barricade on the side of the tunnels. Inside, Chuck finds a huge spinning device which attracts the zombies. Mercenaries operate the device and create an ear-splitting frequency that kill the zombies and harvest the queen wasps that emerge from their remains. Chuck defeats the mercenaries and shuts down the device and the gas. Venturing further inside, Chuck discovers a research lab with scientists monitoring the harvest of the queens. After killing the hostile researchers, he takes their laptop and transceiver which can be used to communicate with the outside world.

Back in the Safe House, Chuck, Stacey and Rebecca discover on the laptop that Phenotrans, the manufacturer of the Zombrex drug, is the company responsible for the underground research facility and unearth a conspiracy using the outbreak to harvest queen wasps from the infected. As Rebecca uses the transceiver to contact her TV station about the shocking news, she is shot and killed by Sullivan, who reveals himself to be in league with Phenotrans. He had breached the Safe House, and freed TK, but TK had instead knocked Sullivan out and attempted to escape alone. Sullivan takes the laptop and transceiver and prepares to kill Chuck and the others, but Stacey hits him with a Baseball Bat, causing him to drop his gun. Chuck takes the gun and fires at Sullivan, who avoids the attack and flees.

Under directions from Stacey, Chuck locates Sullivan on one of the casino rooftops and confronts him. He discovers Sullivan attempting a Skyhook extraction by transport plane. When Chuck demands to know why he and Phenotrans created this outbreak and caused the deaths of many people, Sullivan replies that as more infected people resulted from the outbreaks, they needed more queen wasps to synthesize for the Zombrex drug to keep up the growing demand for it. As there is no way to breed the queens using conventional means, Phenotrans caused the outbreak and used the gas to mutate zombies and harvest more queens from them. He says that Fortune City was considered a small price when compared to the rest of the US, and implies that the Las Vegas outbreak was also caused by them, angering Chuck. TK was hired to set Chuck up as the perpetrator for the outbreak, but Sullivan tells Chuck that TK's later activities were independent from their own, as he became greedy and sought to take advantage. Sullivan insists that they are the good guys as they are providing a service for their customers.

After this, Chuck engages Sullivan in a fight where he emerges as the victor, but is temporarily stunned by attacks from the circling transport plane. Sullivan attempts to extract, but Chuck handcuffs his lower half of the harness onto the platform, causing Sullivan to be instantly killed as his body is severed in half when the plane connects with his harness' sky hook.

Picking up Sullivan's discarded transceiver, Chuck calls Rebecca's TV station and asks them if they want the scoop of a lifetime. He then tells them to bring rescue choppers over to the city. The firebombing is temporarily aborted while rescue choppers are sent in. Arriving on the rooftop of the Safe House in a chopper, Chuck learns from some survivors that Katey and Stacey are missing from the shelter. Heading inside to find them, Chuck refuses to board the chopper and searches the security room. Stacey and Katey are nowhere to be found. Chuck picks up Katey's dropped backpack, and holds it silently as the game apparently ends.

Endings
72 Hour Mode has six different endings, classified from S to F.

Ending S
Method: Chuck completes all cases, but saves TK with Zombrex (TK is Infected). This will unlock the Overtime Mode.thumb|right|300px|Dead Rising 2 Overtime Mode

After defeating Raymond Sullivan and witholding the firebombing, Chuck lands on the rooftop of the safe house, but heads back into the safe house to collect Katey and Stacey. Inside the safe house, both Katey and Stacey are nowhere to be found. Chuck picks up Katey's dropped backpack, and stands there silently with it in his hands as the game seemingly ends.

This leads to Overtime Mode.

Ending A
Method: Chuck completes all cases, but does not give TK Zombrex.

After withholding the firebombing, Chuck lands on the Safe House with the helicopter and finds Stacey and Katey, but Katey drops her backpack. Chuck goes to retrieve it, but just as he is about to pick it up, the zombified TK grabs his arm and forces him into the elevator full of zombies. Chuck throws the backpack to Stacey, shouts for the chopper to lift off, and for Stacey to take care of Katey. As the chopper lifts off, the scene transitions briefly back to the elevator. Chuck is floored by the zombies, while the elevator doors close. Inside, Chuck is seen holding TK off before the screen fades.

A message states that a group of media choppers rescued the living survivors and that it remains unknown if Chuck died from being eaten, infected, if the resumption of the firebombing killed him, or if he somehow managed to escape. Chuck is cleared of the charges due to Stacey Forsythe's information. The outbreak comes to be known itself as "Fortune's End".

Ending B
Method 1: Chuck fails a case after Case 6-1: Help Arrives that allows play to continue, and the time until the firebomb runs out.

Method 2: Chuck fails to catch or defeat Sullivan during The Facts before the time until the firebomb runs out.

A cutscene shows firebombs being dropped upon Fortune City as scheduled, wiping out any remaining survivors and containing the virus. After the scene, a text is shown, saying: Unable to effectively deal with the Fortune City outbreak, the U.S. Goverment dispatched a squadron of bombers to level the city, erasing all traces of life, both alive and undead.

Ending C
Method: Chuck fails the story (before Case 6-1: Help Arrives) but saves Katey with Zombrex and is inside the Safe House when the military arrive.

Method 2: Chuck is inside the safe house at 10:00am on the 28th, but not in the security room.

Chuck, Katey, and Stacey get ready to watch the military rescue, but they hear gunshots and screams. Chuck goes to investigate, but gets shot twice in the chest (by an unseen assailant, most likely Sullivan making his escape) and the screen fades to black. An epilogue reads that the military rescue of Fortune City was considered a failure and it is not known whether anyone survived as the city was firebombed.

Ending D
Method: The only requirement for this ending is for Chuck to be outside the Safe House when the military arrive.

Chuck awakens in the back of a military truck. The soldiers express their disdain at not being allowed to kill Chuck there and then, for they believe he is responsible for the outbreak. Suddenly, they encounter something unexpected amidst the mysterious green gas and the screen fades to black. A message states that Fortune City was subsequently firebombed, eliminating any traces of life, while the outbreak was remembered as the, "Greene Outbreak".

NOTE: Chuck MUST be outside the Safe House when the military arrive to obtain this ending. It literally doesn't matter what else happens in the game as long as Chuck is outside of the Safe House when the 72 Hours are up.

Ending F
Method: Chuck doesn't manage to save Katey with Zombrex, thus failing all/any remaining cases and is still inside the Safe House when the military arrive

Chuck stands inside the Safe House holding Katey's backpack. Stacey tells him not to blame himself for Katey's death, and that they need to get going. Chuck however, doesn't respond, instead he just stares blankly at the backpack. Suddenly, some zombies force their way into the room, and it appears someone has breached the Safe House. Stacey backs off, but Chuck does nothing to prevent the zombies from dragging him to the floor and eating him alive, while Stacey watches in horror, soon to be their next victim. No living survivors were found and Fortune City was firebombed shortly after. The incident became known as the "Greene Outbreak".

NOTE: Regardless of whether Chuck has kept Katey alive with Zombrex or not, being outside the Safe House when the military arrive will result in Ending D.

Alternate Ending F: Chuck fails Overtime by not collecting all requested items/not reaching the Arena in time. Therefore Chuck must complete all case files in order to unlock Overtime.

If going by the alternate method, a cutscene will show TK declaring that Chuck "had other things to do with his busy schedule" and laughs as he lowers Katey and Stacey into the zombies. A final shot shows the rope they are tied to shaking violently as the zombies eat them alive.