Zoe gets with you on the raft, same as Mia did, just when you hit the tanker, Evi kills Zoe (she dries up just like Jack and Mags did). Then from there you play the exact same thing you did saving Mia, doesn't explain how Mia got there, she just is. Then the only difference in that entire section, is when you save Ethan, instead of Mia letting you escape, she chases you with a knife, you pick up a crowbar and fight back, and ultimately kill Mia. So 99% the same, but you see Zoe die and kill Mia; then in the helicopter, instead of Mia being there, it's a phone playing the first video of Mia, you watch it, toss it out, the end. Really not much point in saving Zoe, she dies immediately.