Prologue: Save Joker

Before you start

• None are required. The mission starts automatically after the opening cutscene, whether you import a Mass Effect character or create a new one.
• Importing is optional. Source 20 and the Legendary Edition changes list note that the Legendary Edition starts you with 10 percent of your imported credits, up to 100,000. Another source says importing matters for the Legendary Edition achievement 'Long Service Medal', which needs all three games played with one character. I could not check that achievement against the numbered sources.
• If you are making a new Shepard, expect to wait. Your character cannot be edited until after the prologue and a long cutscene, so you can't change the look or class beforehand (per the research notes).
• There is no quest giver. A squadmate gives the first dialogue prompt.

1. Start: the evacuation exchange

When the opening cutscene ends, Shepard orders the crew to evacuate. A squadmate replies that Joker will not leave the ship. You get a short dialogue prompt here. The wording reported in one walkthrough is 'They'll be here' or 'They damn well better', followed by 'There's no time to argue' or 'I gave you an order!'. Pick either. Gamepressure says the choices before you get control do not affect the rest of this mission. Another source says there are no real choices. Treat them as cosmetic. The ship is on fire and large parts of it are missing.

Checkpoint: You have control of Shepard on the damaged ship and can walk, with flames and small explosions ahead.

2. Walk forward and climb to the upper level

Ignore the fire and the small explosions. There is nothing to fight or pick up. Keep moving straight ahead past the wreckage until you reach a staircase, then climb it. StrategyWiki describes the same route: around the remains of the mess hall, then up the stairs on your right toward the flight deck. If the lighting and damage confuse you, remember there is only one way forward.

Checkpoint: You are on the upper deck and can see the large hull breach ahead.

3. Cross the breach to the cockpit

On the upper deck, a big section of hull is destroyed. Head toward the pilot's cabin at the front of the ship. A blue force field holds the atmosphere in. One wiki calls it a kinetic airlock. Walk through it to reach Joker. Exact on-screen prompts were not confirmed in the sources, so if nothing prompts you, just keep moving toward the cockpit.

Checkpoint: Reaching Joker triggers a dialogue cutscene.

4. Persuade Joker to leave

Joker thinks the ship can still be saved. Answer him to change his mind. The reported options are 'Don't throw your life away' (the polite one) and 'Don't be stupid!' (the aggressive one). No morality points are awarded and both options lead to the same result: Joker gives up and agrees to go. Which squadmate appears in the conversation depends on your imported save, if any (see decisions).

Checkpoint: Joker concedes and the scene moves on without a fail state.

5. Take Joker to the escape pod

After the conversation, Shepard carries Joker to the escape pod and secures him inside. This is scripted and you have nothing to do except let the scene play. You can't save or open certain menus during the mission.

Checkpoint: Joker is strapped into the pod and the scene continues without your input.

6. The forced ending

The attacking cruiser fires again. The blast throws Shepard away from the pod, so Shepard launches the pod with only Joker inside. A death cutscene follows, and the mission ends there. Let the cutscenes finish. The next mission is Prologue: Awakening, which begins after a long cutscene.

Checkpoint: The death cutscene plays, then the story moves on to Prologue: Awakening. The achievement 'Missing in Action' may unlock around this point (see troubleshooting).

Choices and things you can miss

• Dialogue wording: the options at the start and with Joker are cosmetic. The sources say they do not change this mission or award morality points.
• Imported save: the conversation reflects whether the Citadel Council was saved or lost. A new character defaults to the Council having been lost. I did not verify the exact line differences.
• Which squadmate appears: Ashley, Kaidan or Liara. Fandom says Liara appears only in a new, unmodified game or if she was Shepard's love interest in an imported game. A 2010 talk-page comment says a new male Shepard gets Ashley and a new female Shepard gets Kaidan, and an unromanced import gets whichever of Ashley or Kaidan survived Virmire. That comment is user-reported and its wording differs from the Fandom article, so treat the new-character claim as unconfirmed.
• Import or new character: importing is optional. A new character gives you the default state without your earlier choices, so decide before you start if you care about carrying choices over.

Rewards

• Achievement or trophy 'Missing in Action', described as 'Save your crew from an overwhelming attack'. It is worth 5 Gamerscore on Xbox and is a Bronze trophy on PlayStation. These values are from the research notes and were not checked against a numbered source.
• No items, credits or experience are listed for this mission.
• The mission unlocks Prologue: Awakening.

Troubleshooting

• The achievement does not pop right away: user comments say it unlocks during or after the cutscenes, one saying after the cutscene that follows Shepard's death. A Japanese-release commenter says it unlocks during the death cutscene or the one after. Let all the cutscenes finish before deciding it failed. These are user reports.
• You can't save or use certain menus: this is intended in this mission, not a bug.
• You feel lost: go straight, climb the stairs, cross the breach through the blue force field and walk to the bow. There is only one path.
• You expected combat, wall safes or credits: those belong to the next mission, not this one. One walkthrough that mixes them in covers later content.

Release and platform notes

Base game (2010): this is the baseline, with a linear route and no combat. PS3: Fandom trivia says Liara always appears on the PS3 version even when importing a Mass Effect save, and Fextralife repeats this without a reason. Legendary Edition (2021): Fandom lists adjusted cutscene camera angles (notably with Miranda on the Normandy), 10 percent of imported credits up to 100,000, and a new set of achievements. I found no documented change to this mission's route or objectives. Not verified: exact on-screen prompts, coordinates and timers.