"Hell is Other People"

If one line can sum up No Exit, it's this one. As Garcin, Inez, and Estelle soon realize, Hell is in fact not the stereotypical, fiery doom, and torturous device-y place we imagine it to be. There are no hot flames or pain, just people. It really doesn't seem that bad at first glance. You can learn to tolerate the people you're with and maybe even hope to befriend them. Regardless, you're not in total physical agony at all times. So what's the problem? The Gaze. 

Garcin, Inez, and Estelle can never be alone again. They can never try to forget their actions in life because they each serve as a constant reminder to the others. They can never attain closure, and their memories will haunt them eternally. Most importantly, they will never be able to finally shed their fabricated outward dispositions and be themselves. Everyone's different when they're alone; when you're under the speculation of anyone else, you change. For some, like Estelle, you want to look your best. For others, like Garcin, you want to appear stronger. But, when you're alone, you're comfortable with who you are underneath the lipstick and news articles. There's a sense of security and ease when you know what you are is all you need to be. But, Garcin, Estelle, and Inez will never be able to experience this feeling. They will always feel pressured to look and behave a certain way under the scrutiny of others. Moreover, they can never relish in a few hours of sleep or even a millisecond of blinking to escape reality. In this way, they will have the company of each other for eternity, but they will be forever alone, trapped in the existence they have created for themselves. Freedom cannot even be dreamed of. 

Sounds like hell to me.