User blog comment:Saratje/The Great Paarthurnax Conspiracy/@comment-3470121-20120417020753/@comment-212.183.128.100-20120429201148

Right, so if Alduin was able to leave the time tunnel as long as the scroll was read a second time, what's stopping him from reappearing 20 seconds later, killing the heroes and then commanding the dragon cult to open the scroll. As long as it gets opened a second time while alduin lives there'd be no paradox.