Liang lives near the Chinese Wall. Every night he sees the sun disappear behind the great shadow to the west and wonders what's on the other side. His old grandmother, who knows a story for everything, told him that a huge dragon lies there and that he swallows the sun each evening to let him rise again the next day ... Impossible, says Liang, dragons do not exist ! But there is nothing greater than the curiosity of a child ... except maybe a dragon? Liang must make it clear !