I saw an ad recently, posted by the Berlin transportation service (Berliner Verkehrsbetriebe), captioned, "was alles geht, wenn man vorher nicht fragt."
What is the force of "alles" here? Is it simply "what all happens when..." or "all that happens when..."? "was" here is not short for "etwas," is it? I would have understood more clearly had the sentence read, "was geht, wenn..."