Battle of the Five Armies - Smaug discovers the theft

Bilbo Baggins bravely put on the One-ring and, invisible, descended into the dragon's lair. To prove his daring, he took an insignificant cup from the great pile of treasure. Although Smaug possessed innumerable riches, he knew every piece, large and small. Enraged at the theft, he chased the hobbit through the tunnels and smashed his way out of the mountain.