Timmy is so excited about his new suit that Ellen allows him to wear it until Jeff gets home, but when he tears it, afraid they will send him back to his aunt and uncle, Timmy lies and lays the blame on Lassie. To make him confess, Ellen makes him decide Lassie's punishment.

A flooded river threatens to sweep away a bridge construction project. Ranger Corey Stuart and Lassie brave the raging waters in a small boat to construct a log chain barrier and control the flow of water and logs.