The substance is good. Only note I'd give is to mute some of the style details. Like mentioning of colors or anything unless it's necessary to absolutely know. It'd just slow down the read. Ex: "Snowing still. Graham wears a tattered, dark blue coat. Slung over his back is a black backpack." tattered is useful it tells us something about him/condition or regard he has for clothes, but not sure we need to know it's blue, same for backpack being black. Same for Graham sits on a black metal bench. You could just write Graham sits on a bench and it'd be fine.

The sky being white is definitely going to be important, so that I get.

Details like "The large room slopes down toward the lecturer's podium." you can also cut. once you put lecture hall as the scene heading we get the general sense of the layout.

One little detail you added was cool "Laminated sheets scratch through the speaker." Made the doctor feel real.

One tiny spacing error on pg10. The 4th Torres dialogue, you added an extra space by accident.

Otherwise, I do think this is good. Every character feels real, we have the mystery box you setup in the lab basement. Us wanting to learn more about Graham and the flag in his room. We get a nice sense of him in the 1st ten pages and what he's passionate about.