Question about making brownies?!

Question about making brownies?

So I just bought Duncan Hines brownie mix. The recipe calls for two eggs and I had that exact number of eggs left in the carton until I accidentally dropped one of them a few minutes ago. Clumsy me! The store is now closed so I can't go buy more eggs. My question is will my brownies still be edible if I make them with one egg as opposed to the two the recipe calls for?

14 hours ago
Should I add more water to the mix to compensate for the lack of egg in it?

14 hours ago
I have exactly 1/2 cup vegetable oil left which is exactly what the recipe calls for!

4 hours ago
Just to let everyone know, the brownies turned out awful! I tried substituting 2 tbsp. of cornstarch for the egg, but it still didn't turn out right.

One egg-it will be a little more dense. Just add the secret ingredient,and they will be fine.(See That 70's show-season 2-The Garage Sale).