Choice: Side with Jack or Miranda?
After completing the Horizon mission, many of your squad members will ask you to help them with a personal mission (known as a Loyalty mission) when speaking with them on the Normandy. Both Jack and Miranda have their own mission but if you complete them both, you will find yourself called to the briefing room upon returning to the Normandy where Jack and Miranda are having the mother of all cat fights. Two powerful biotics fighting could get ugly so Shepard has to intervene somehow. The consequences of each decision can be found below:
Siding with Jack
If you choose the option “Back off, Miranda”, you will lose Miranda’s Loyalty and any relationship you had with her, potentially risking her life for the final mission. You will retain Jack’s Loyalty and any relationship you were pursuing at the time.
Siding with Miranda
Alternatively, choosing the option “Too bad, Jack” will similarly alienate Jack, losing her Loyalty and any relationship you had. Miranda will retain Loyalty and relationship status.
Keeping Both Jack and Miranda’s Loyalty
Even if you are forced to choose a side, there is a way to regain the Loyalty of the alienated companion by talking to them again and passing a slightly lower Paragon/Renegade check. If you didn’t have enough points the first time, be sure to gain more and talk to them later to regain their Loyalty but do be aware that any relationship you had will not be rekindled with this method.
Fear not, however: there is a way to retain both companion’s Loyalty the first time. If you have a very high Paragon or Renegade score, you will get a unique dialogue option which will automatically defuse the situation, helping both women come to an understanding and retaining their Loyalty for the rest of the game, as well as any relationship you were building. This Persuasion check is incredibly high (slightly less Renegade than Paragon points is needed) and is based on a percentage of all the points available in all the missions and assigments you have completed up to that point. This can vary throughout the game but if you leave one of their Loyalty missions till close to the end of the game, and you diligently accumulate the requisite points when you can, you should be able to unlock this option. Note the meter is not a great indicator of your ability to pass this check.