On the edge of the Gobi desert in Northwest China, Lang returns to his hometown after being released from jail. While working for the local dog patrol team to clear the town of stray dogs before the Olympic Games, he strikes up an unlikely connection with a black dog. These two lonely souls embark on a journey together.
In the 1940s, the world was in turmoil, and it was crucial to decipher the enemy's communication codes in a timely and accurate manner. Rong Jinzhen has shown amazing mathematical talent since her childhood, and because she solved the problems assigned by her math teacher, she was noticed by more people, and even walked into the door of code-breaking by mistake.
Set in the 1980s, troubled youth Chan Lok-kwun accidentally enters the Walled City, discovers the order amidst its chaos, and learns important life lessons along the way. In the Walled City, he becomes close friends with Shin, Twelfth Master and AV. Under the leadership of Cyclone, they resist against the invasion of villain Mr. Big in a series of fierce battles. Together, they vow to protect the safe haven that is Kowloon Walled City.