- Tutorial – Reaper Arrival (aligned with Systems Alliance)
- Shepard wakes up to the sound of someone ringing for him. He is lying on a bed, apparently taking an afternoon nap.
- If Shepard was a Spectre in ME2, he wakes up in an apartment complex overlooking the city of Vancouver.
- If Shepard was not a Spectre in ME2, he wakes up in a white cell-like chamber, with only a few items in the room (a bed, a sink, etc).
- When Shepard approaches the door, it opens to reveal James Vega, Shepard's “Alliance-designated leash”. Apparently James stands guard over Shepard, and has been outside the door since Shepard slept. James asks Shepard how he is feeling. Shepard can reply several different ways to James's question, and his answer engraves the kind of relationship he has with his guard.
- Shepard can have a friendly and cooperative relationship with James.
- Shepard can have a professional and respectful relationship with James.
- Shepard can have a cold and uncooperative relationship with James.
- As they move throughout the building where Shepard is being housed, it becomes apparent that something is wrong. Alliance personnel are rushing about hurriedly, conversing with each other and talking in whispers. Few people pay Shepard and Vega any attention. The two soldiers meet up with Donnell Udina/David Anderson (depending on which one is not a Citadel Council member), who is waiting to escort Shepard to a meeting. Udina/Anderson senses that something is wrong, but doesn't say anything. Instead, he comments on their destination and purpose: Shepard is being lead to meet with Alliance Parliament to discuss the batarian-human situation after the destruction of the Bahak System (which is now a supernova).
- Vega leads Udina/Anderson and Shepard to an important looking room, and waits outside. Shepard finds himself in a large chamber before the Alliance Parliament. They tell Shepard that less than 4 hours ago, the Alliance communication buoys stopped reporting in, and that the Alliance has just lost contact with Lunar Base.
- Shepard can be horrified at this news (paragon)
- Shepard can be expecting this news (neutral)
- Shepard can be angry at this news (renegade)
- Regardless of which response Shepard chooses, he will instantly know what's about to happen: the Reapers are going to invade the planet.
- Udina reprimands Shepard, and tells him not to jump to conclusions.
- Anderson supports Shepard, and tells the Parliament that they should've listened.
- The Parliament looks shaken, and decides to accept Shepard's warning. An Alliance officer charges into the room, and prompts everyone to look at a television screen. ANN (Alliance News Network) on the wall monitor show a number of Earth's cities being destroyed by the unmistakable figure of Reapers. The Alliance asks Shepard for advice on what to do, and Shepard will prioritize a response:
- He can tell the Alliance to evacuate the city (paragon)
- He can tell the Alliance to contact the Citadel Council for aid (neutral)
- He can tell the Alliance to ready their military (renegade)
- The Alliance will begin to instantly follow Shepard's orders (they accept that he knows what he's doing, since he was right all along), but they are cut short by explosions from outside the building, followed by monumental screaming, and a strange, deep, mechanical horn. Then the room will be blasted apart. Shepard will be thrown to the floor, but will recover get to his feet. Alliance Parliament flees the room while shouting orders, and Udina/Anderson members will rush through the smoke to Shepard.
- Anderson hands Shepard a spare gun, and tells him that they need to get to higher ground, and contact the Normandy (the Reapers are blocking radio signals all over Vancouver).
- Udina hands Shepard a gun (but is unarmed himself), and tells Shepard to escort him to the escape shuttles so he can make go to the Council.
- Shepard exits the room to find that the building has been blown open, and husk forces are pouring into the the building, shooting Alliance workers without remorse. Anderson/Udina calls out for James Vega, but he is nowhere to be found. Shepard fights his way through the base with:
- Anderson as a squad mate.
- Udina as a non-combative escort.
- Whichever squad-mate Shepard has, they will find a security monitor room, and will scan it for a safe way to the roof of the building where they can hope to send a signal to the Normandy/shuttles for pick up. Anderson/Udina notice James Vega fighting husks not far from them on the monitor, and recommends meeting up with Vega to save him, and sync up communication with the Normandy – Vega has a communications device that links directly to the SR2 and a personal security shuttle, and Shepard's was confiscated to prevent any attempt to escape Earth prior to the Reaper invasion. After plotting a safe route to Shepard's omni tool, the squad-mate leaves the room, and Shepard is about to follow, when he notices something on the monitor: a small boy walking through an empty hall. But there is nothing Shepard can do for him, so he follows Anderson/Udina.
- Shepard and his squad-mate meet up with Vega, fight off husks. While Shepard had been talking to the Alliance Parliament, James was distracted by a news feed on “some kind of explosion” that devastated London. Then some kind of explosion rocked the building, and James and the Alliance soldiers were attacked by horrible creatures called “husks” similar to what had been seen on Eden Prime three years ago. James had been cut off from Shepard's room, and had to retreat. The company establish a link to Joker and EDI, who are powering up the Normandy almost single handed (Joker comments on how only a few crew members are aboard). A shuttle comes up to the broken window near where they are standing (high above street level)--
- Anderson jumps on board the shuttle. Shepard tells him to get to a ship and make for the Citadel, while he and James prepare to find the Normandy. Anderson will exclaim that he is instead going to help the soldiers on Earth, and that he'll be more valuable here.
- Udina jumps on board the shuttle. Shepard tells him to get to a ship and make for the Citadel, while he and James prepare to find the Normandy. Udina departs.
- Shepard and Vega fight their way to the roof, and finally see what's happened to Vancouver. The Reapers are there in force, at least half a dozen of them, each machine dwarfing the skyscrapers they are walking next to. Shepard and Vega manage to pinpoint a rendezvous location down near the harbor. James attempts to call in a gunship to carry them to that position, but the incoming craft is shot down by enemy Oculus drones, so Shepard and Vega proceed on foot.
- The two fight their way inside of a destroyed apartment complex, and Vega finds a door that is too damaged to open with an omni tool. While James attempts to pry the door open, Shepard hears a noise coming from a ventilation shaft, and goes to investigate cautiously. It turns out to be the same boy he saw on the monitors earlier.
- Shepard can tell the boy that he is there to help
- Shepard can tell the boy to stay hidden
- Shepard can tell the boy to flee
- The boy will comment on how there is no hope, and how everyone is probably going to die. Shepard opens his mouth to reply, but at that moment James succeeds in pushing the door open, and distracted, Shepard looks away from the boy. James asks Shepard who he is talking to, and Shepard will glance back into the vent, only to discover that the boy is gone. Paragon and renegade prompts flash on screen:
- Paragon prompt has Shepard call into the vent for the boy. Vega says “whoever you saw, he'll just have to hang on”
- Renegade prompt has Shepard pretending he didn't see anyone.
- Shepard, and Vega, make their way to the Normandy, which is hovering in the bay. The cargo door opens allowing them to jump on board, and Ashley Williams/Kaidan Alenko comes out to provide covering fire, killing several husks who attempt to follow them. The Normandy departs the planet, and thus begins Mass Effect 3.