White screen on node view

I created a new steps node, filled in the steps with two page nodes, and saved. It took me to the node page, which is white screen, and the front page, which includes a node teaser view, is also white screen. Looking at the code, the call to exit() seems to be the cause. I'm not sure what you were trying to do there, but you should never use exit(), as it completely stops Drupal from running. Maybe you wanted return there to leave the function? I see a few other calls to exit(), which should all be changed.

The root problem seems to be that $step = steps_get_session('step'); is returning nothing, so it has no node to load. Shouldn't I always be on some step?