After the completition of Quinn's and Seeker's quests switch to Miranda. Switch to Quinn. Switch back to Miranda. Guard with food should arrive.
Get pillow and stuff it down the toilet. Remove ligt bulb from light fixture and attach wire to lighting fixture. Grab metal tray from bed and attach it to other end of wire. Now push toilet flushing button and try to look innocent.
Stride in from the unbarred door and grab toolbox. Back to your cell and open ventilation grille with a laser hackshaw.

Miranda has to make it to the opening labelled "escape". Every grille has an animation or two behind it so it's really advisable to watch them all. Miranda should remove "escape" vent shutter when scientists are gone. She can go towards north and explore Tnuctip's fate and/or she has to enter door to the east. She should boldly activate controls regardless of threath to all humanity.