Can someone explain me this sentence and what does "being foiled" mean in the context below? "Amid shrieks and wailing and the shouts of men he came over them, swept towards the bridges and was foiled!" In the book The Hobbit, the dragon Smaug flies to destroy a town (the lake-town Esgaroth) but I think he is, kind of, "prevented" from doing so, according to my dictionary. How is blowing up a bridge a problem for a dragon to destroy a town? Or do I misunderstand something?