Modrin Solus is a vital character in Mass Effect 2, and players will need to try and find him in less than ideal circumstances. Mordin is running a clinic on Omega, trying to help the victims of a strange plague. To find him, players will need to get into the quarantine zone, then get him out of there.
To find the quarantine zone, players will need to make their way to the Apartments. Head inside the door and down the corridor, then look to the right where another corridor branches off toward a red door with a guard. This is the quarantine zone. Speak with the guard, then tell him to let you inside so you can help.
It is a good idea to take a human crew made up of Shepherd, Miranda, and Jacob, as any aliens will be susceptible to catching the plague. He deep into the area and try to help anyone that you find, and make sure to explore any side rooms.
Eventually, you will arrive at the clinic where Mordin Solus will ask you to help him. Players will need to go to environmental control in order to help Mordin, and this is all pretty straightforward. All players need to do is follow the only possible path through the station and activate the fans at the end.