In this new thriller in the exciting "Moose Jaw Adventure" series from best-selling writer Mary Harelkin Bishop, Andrea Talbot takes an unwilling third trip to the spooky tunnels under Moose Jaw and uncovers the exploitation of Chinese immigrant workers.

Andrea has already had two adventures in the notorious Moose Jaw tunnels. Travelling back in time to the 1920s, she's been forced to work for Al Capone (Tunnels of Time) and helped shut down a ring of thieves (Tunnels of Terror). But it's scary down in the tunnels, and she has no desire to go back. That part of her life is closed! Then her friends Kami and Eddie Wong are accidentally thrust into the tunnels.

Andrea, now fifteen years old, has no choice but to go back in time to rescue them - with the help of her ten-year-old brother Tony. She finds a shocking new problem in the tunnels. Indentured Chinese workers toil in miserable conditions, for pitifully small wages. Smuggled into Canada by unscrupulous operators, they have no choice but to keep working - to save money to pay the infamous Head Tax the Canadian government imposes on Chinese immigrants.

In this harsh world, Kami and Eddie are mistaken for indentured workers. Kami is sent to work in a laundry, Eddie to unload produce in a grocery store. Andrea is outraged at the treatment of the Chinese workers. Many people are profiting from this ruthless exploitation, none more than the nasty crook in charge of it all, Mean-Eyed Max. Andrea has to save her friends, but what about the other workers? With the help of her friends and the mysterious Mr. Wong, she and Tony help catch the bad guys and rescue the workers too.