In Prey, after the Cargo Bay mission, Morgan Yu must get to the reactor control room in the power plant station. This is a massive area with lots of enemies, so a step by step walkthrough approach is necessary.
First, get to life support from the Cargo Bay.
When you enter life support, the whole area is in a mess. Explore life support. Also Mikahaila Ilyushin contacts you from the coolant monitoring room.
So make your way into reactor control doors, except after a while, Morgan realizes this is not the doors that lead into the reactor control room, but the one that leads further into the massive power plant.
The doors that lead into the reactor control room are not working, by the way, due to the intervention of one of our favourite typhon – the Technopath.
Get into the water treatment facility to get to the technopath.
Eliminate the technopath. Blast it into oblivion.
Get to Mikahaila Ilyushin in the coolant monitoring room.
Then get to the actual reactor area.
Go down the stairs. If you wish to fight the nightmare, charge in. Otherwise keep climbing down stealthily.
Get into the access control room by defeating the nightmare, or turn into something small and fall down inconspicuously.
There you are – Morgan Yu is at the control room.