All non-sheepherding dogs have been outlawed from the rocky coastal village where Maggie lives. Unwilling to give up her beloved Newfoundland, Sirius, Maggie defies the law and hides Sirius away.

But when a steamer crashes into the rocks during a violent storm and starts to sink with a hundred passengers on board, Maggie faces a difficult choice. She knows Sirius can help rescue the people trapped on the ship, but bringing him out of hiding would put his own life in jeopardy. Is Maggie's brave dog a big enough hero to save the desperate passengers—and himself?

This heartwarming story of a lovable dog and his feisty mistress is based on true stories about Newfoundland dogs and filled with drama, tension, and exciting rescues.