Operation: The Scientist Salarian

Special Tasks Group (STG) // Medical Log: Mordin Solus // Clearance: Shepard

"Had to be me. Someone else might have gotten it wrong."

This is widely considered the most heartbreaking moment in the Mass Effect trilogy. Most players assume Mordin Solus simply must die to cure the Genophage. It feels like a fixed point in time—a heroic sacrifice that cannot be avoided.

But that assumption is wrong.

There is a way to save Mordin Solus. He can survive Tuchanka, join the crucible project, and live to see the end of the war. However, the cost of his survival is high. To save the doctor, you have to doom a species.

Phase 1: The "Monster" Prerequisites

You cannot save Mordin by making a simple choice in Mass Effect 3. This outcome requires a specific "Renegade" history that spans the entire trilogy. If you have played a heroic Paragon, Mordin will refuse to back down and you will have to shoot him or let him die.

The Checklist of Doom

For Mordin to be convinced that the Cure is a mistake, the following must be true:

Wrex must be DEAD: You must have killed Wrex on Virmire in ME1. His brother, Wreav, must be the leader of clan Urdnot.
Eve must be DEAD: In ME2, you must have chosen to destroy Maelon's data during Mordin's loyalty mission. Without this data, Eve (Bakara) will not survive the stress of the procedure in ME3.

The Logic: If Wrex is alive, he will guide the Krogan to peace. If Eve is alive, she will temper their aggression. If both are gone, the Krogan are led solely by Wreav, a violent warlord who openly plans to start a new war the moment the cure is dispensed.

Only under these specific conditions will Mordin realize that curing the Genophage might be a catastrophic error.

Phase 2: The Tower Scene

If you meet the conditions above, proceed with the mission Priority: Tuchanka.

When the Dalatrass offers you the deal to sabotage the cure, accept it (or stay silent). Do not reveal the sabotage to the Krogan in the truck.
At the final tower console, Mordin will prepare to disperse the cure.
You must try to stop him. A dialogue wheel will appear.

The Critical Conversation

Because Wreav is a tyrant and Eve is dead, you can use the Reputation check:

"Why cure them?" / "Not now."

Shepard will argue: "With Eve dead and Wreav in charge, this won't lead to a renaissance. It will lead to war."

Mordin, relying on logic, will pause. He will look at the data. He will realize you are right.
"I made a mistake. focused on big picture. Big picture made of little pictures. Too many variables. I... I am not sure."

He will agree to fake the cure deployment. The Shroud will disperse a placebo. The Krogan will think they are cured, but they are not.

Tactical Appendix: The Outcome

The price of a life.

File: Status Report

Mordin Survived: He goes into hiding to work on the Crucible project. He provides 25 War Assets.
Salarian Support: Because you sabotaged the cure, the Dalatrass gives you the full Salarian First Fleet (150 War Assets).
Krogan Support: Wreav is too stupid to realize the cure was fake. He pledges the Krogan clans to you (300+ War Assets).

Tactical Summary: Mechanically, this is one of the highest War Asset outcomes in the game. You gain the full strength of both the Salarians and the Krogan, and you save a beloved friend.

Moral Cost: You have deceived an entire species and condemned them to slow extinction to win a war.