I've played with this idea for some time now. I've finished Dead Space 2 around four times out of sheer enjoyment of what a good game it is, and I put a lot of thought into what I would like to see if EA continues the franchise with a third Dead Space game. Some of my ideas won't be liked by a lot of fans, but I think they make a compelling narrative.
The third Dead Space should take place twenty years after two, but I don't want it to start twenty years later. I want it to start one year later. Isaac and Ellie have found a home on a small industrial planet and are married. Ellie has just recently given birth to Isaac's child. This small portion of the game will serve as the tutorial/first level of Dead Space 3. It will also be the only time during the game that Isaac Clarke is playable. Isaac will do chores around his place that will introduce the mechanics of telekinesis, zero-gravity movement, shooting etc. Then, Isaac returns to his home and he and Ellie watch the sky. Just then, a blazing streak of fire lights the air and an impact explosion can be seen in the distance. Isaac runs to turn on the TV, and it is revealed that the impact was from a ship of some sort that is filled with infected crew. The necromorphs are taking over the city near Isaac's home. Isaac knows that he is the only one on the peaceful planet who can stop the outbreak, and hurries over there. After fighting through hoards of necromorphs to the power plant in the middle of the city (Offering a refreshing change of scenery as Isaac fights the necros in daylight, outside on a sunny day), Isaac realizes that the planet can't be saved, and rigs the generators in the plant to overheat, knowing the ensuing explosion will destroy the planet. He calls Ellie and tells her to leave the planet with their son, and that he loves her. She complies, and her and the Clarke baby flee the planet in a small ship. Isaac fights off a last wave as he waits for the generators to overheat, and goes out with a bang. The core of the planet becomes unstable, and the entire world is destroyed. In the ship, Ellie watches tearfully as she turns on a communicator to get help, only to realize that Necromorph outbreaks are being reported all over the universe as ships and comets carrying the infection touch ground with human occupied planets. Fade to black.
Now, nineteen years after Isaac sacrifices himself to save his family, his son and wife are living on a large, beat up ship, part of a convoy of humans constantly searching for planets untouched by the necromorph outbreak to settle down. The new Clarke knows little about his father, but constantly meets people who know what Isaac did during his life and they all talk very highly of him. The Clarke son has to step into his father's shoes abruptly, however, when The Convoy is infected. (This portion could consist of one to two levels of the game, culminating with a boss fight against Clarke's mother, who has been infected). The Clarke son (I don't know if you've noticed by now, but I have no clue what to name him) destroys the convoy and flees to the nearest planet. That planet houses a Marker, which although having no clue what it is, The Clarke son is compelled to destroy it (via hallucinations of his father. Isaac will in a sense, become the new protagonist's Nicole). After fighting through several different locals on the planet (Police station, public pool, old jail, mining station) to collect necessary items, the Clarke Son destroys the Marker with a mining drill (Ideally, this section would last three to four levels), and when the Marker cracks open, a bright light appears. The Clarke Son walks into it, and has a vision. He sees the original Marker and the planet it is on. He meets Isaac, who, until this point, he didn't know was his father, and Isaac and him have their only "father-son" moment. Isaac tells his son to finish what he started, and the Clarke Son promises he will. The Clarke Son leaves the planet on his ship, and sets his coordinates for the planet housing the original Marker. The camera pans to look at the on board navigation, and it is revealed that the destination is Earth.
The Clarke Son lands on Earth just as Earthgov and the Unitologists break out into civil war over issues of Church and State. The Clarke Son tentatively joins with Earthgov to break through Unitologist lines and reach the Master Marker. The Master Marker is in Southern Africa, where The Clarke Son and the Earthgov troops break through a large Unitologist compound to reach The Master Marker (This gameplay section would feature human on human combat, and would last only one level. Marks a significant change in traditional DS gameplay, as no necromorphs appear and the player character is never alone during the level). Upon reaching the Cathedral of the compound, The Earthgov troops and The Clarke Son are met with a gruesome scene. The Unitologists inside have committed a mass suicide, hoping to activate the Master Marker and unleash an unparalleled Necromorph infection large enough to consume the galaxy. It is here that it is revealed the head of Earthgov isn't on the planet, but is on the moon. He contacts The Clarke Son, and shares with him that Earthgov plans on activating the Master Marker to purge the universe of Unitologist, thanks to a misguided belief that has developed among Earthgov that only Unitologists are affected by the Marker. The Earthgov troops accompanying the Clarke Son are ordered to kill him, but he escapes. The Master Marker is activated by the Earthgov on the moon, and the compound becomes a breeding ground for Necromorphs. Surrounded and alone in the middle of South Africa, The Clarke Son fights his way through the giant Unitologist compound to an escape shuttle on the other side of the compound (This should consist of three to four levels of sheer horror gameplay). On the way to the shuttle, The Clarke Son finds the room containing the Marker. Here, it is revealed that the Marker on Earth isn’t the Master Marker, and that Earthgov has taken it up to the moon. He enters, and suffers a severe mental breakdown. The Clarke Son destroys the Marker after a fight with his subconscious "Dead Space 2" style. During the battle, The Clarke Son faces his own insecurities, manifested in the form of several variants of Isaac Clarke, some Necromorph, some not. They taunt him and tell him that he will never accomplish what his father has, and that he is only a tenth of the man Isaac was. After defeating his insecurities, the Marker cracks, and another bright light emerges. He sees visions of his family, necromorphs, and an unknown woman. Isaac urges his son to find her, because destroying the Master Marker won't be enough now. The necromorph infestation has become too large, and the only way of escaping it, is immunity. The universe needs a mass produced vaccine, along with the destruction of the Master Marker, to ensure there is never another outbreak. The Clarke Son asks his father who the woman is. Isaac's reply: "Lexine Weller". The Marker begins to crumble to the ground, and The Clarke Son leaves Earth on the escape shuttle. The Earthgov C.O. contacts The Clarke Son and asks what he has done. He promises that Earthgov won’t rest until he has paid for his actions. The Clarke Son calmly replies that Earthgov will face their judgment soon enough.
The Clarke Son travels to a small outpost on an asteroid orbiting Neptune. Here, he finds Lexine Weller and her daughter, Sarah, living in a small research facility with very high security. A few other humans are found here as well, including a scientist. When the Clarke Son tells Lexine about his experiences over the past couple weeks, she tells him that she knows exactly why he was led to her. She explains that although The Clarke Son has a very high immunity to the Necromorph infection, he is not completely immune. Neither is Lexine, as she continues to explain, but her daughter, Sarah, is. They consult the scientist on the planet to see if a vaccine can be created. He tells them that it is possible, but not without a pure sample of necromorph tissue. The Clarke Son offers to retrieve the flesh of dead necromorphs, but is informed that the flesh is useless as it is human flesh manipulated by the virus. To be successful, The Clarke Son needs to retrieve the purest form of Necromorph flesh available. The scientist says that he might be able to find some on another nearby asteroid, where the Necromorphs have fused with micro-bacteria to form a gelatinous super being (reminiscent to but not entirely like the Slug boss from Dead Space 1). The Clarke Son travels to the planet and destroys the being, and gathers a sample of its flesh. He brings it to the scientist, (in a completely sterile, one-hundred percent contamination free room) who is wearing a hazmat suit to avoid contamination. Sarah is brought out without protection. The necromorph virus fails to infect her blood, even when directly inserted intravenously. The virus dies from contact with her blood. The scientist takes samples of her blood and finds a gene she has that is an irregular mutation. He finds a way to replicate it, and claims that with a proper facility, he may be able to mass produce it. The Clarke Son replies that he “knows a place”. (Note: section of gameplay should last one to two levels. More so about story development than actual gameplay.)
The Clarke Son, the scientist, Lexine, and Sarah all arrive on the Earthgov Moon base. There, they find that the virus has reached the moon base and the entire Moon is infected. The Clarke Son fights through the infection to a large, secure laboratory that has managed to avoid infection. Several Earthgov scientists in the room surrender to The Clarke Son, fearing the Necromorphs. The scientist from Neptune begins to consult with these scientists and Sarah and Lexine remain with them for testing. Meanwhile, The Clarke Son boards a lunar train to the dark side of the moon, where the headquarters for the Earthgov Moon base are located. Here he faces heavy resistance from necromorphs as he fights his way into the facility (Two to three levels as he goes deeper underground). When he finally reaches the core of the Moon Base, he meets the C.O. of Earthgov. The man is severely mutated, appearing half necro, half human. He then proceeds to explain that Earthgov was working on a vaccine as well. He took it, believing that it would work. Instead of killing the virus, however, it mutated it, and allowed it to merge with his human form. The C.O. and The Clarke Son square off, and after a large, devastating battle; The Clarke Son comes out victorious. He boards the elevator to the level below, the deepest level of the Moon Base. Here, the Master Marker is kept. The final boss battle is The Clarke Son versus himself. The Clarke Son fights himself in his subconscious, from fear of what he has become, and what he has done to destroy the Necromorphs. The Necro version of him continues to mutate until it is an unrecognizable hulking monster. The Clarke Son defeats it, and the Master Marker shatters. Scenes of necromorphs around the universe melting into piles of flesh play. Clarke sits down, takes a deep breath, and grabs a shard from the Master Marker. While turning it in his hand, Sarah contacts him and tells him that he was successful, and that it’s finally over. Clarke, while staring at the Marker Shard, scoffs. The Marker Shard lets off a warm green glow, and Clarke looks up at the camera. His left eye is glowing the same shade green as the Shard. With a smirk, Clarke asks “Is it?” Cut to credits.