So I'm doing the quest Discerning The Transmundane given by Septimus Signus and I'm in Blackreach and have entered Sinderions Field Laboratory and everytime I go to the leave laboratory and enter back into Blackreach, as soon as it stops loading I instantly die. I believe it's because of the dwarven arrow launcher aimed right at the door but I have already launched the arrows. I'm not sure if that's the reason why I keep dying but that's my theory. So now I'm stuck inside the laboratory with no prior saves. Help.

If you have no other saves then there might not be much we can do.

Are you on PC, if so you might have an option to get past with console commands.