The first method that comes to mind is to send the information through a get/post-variable. When you perform the session-check at page21 (I assume) and redirect the user to the login page, you can append the pagename to the address, i.e. Redirect to something like www.xyz.com/login.htm?page21 (or if you don't want the pagename to be visible, use post instead).
Then simply use that information when the user logs in again to redirect him/her to page21.
If you are using forms authentication, there is an inbuilt mechanism to do that, here it is. It will automatically redirect the user to the URL Referrer page.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.