Jeff is failing arithmetic due to his problems with fractions, so Ellen tells him he may not go to the circus if he doesn't pass his next test.

To make up for ignoring Jeff, Gramps brings him home a colt Jeff names ""Domino."" Jeff then starts ignoring Lassie in his enthusiasm over having a horse.

Gramps hires a tramp to do some odd jobs on the farm, then is jealous when Jeff starts to idolize the tale-telling old man.

When Gramps quarrels with Matt Brockway after a hotly contested checker game, both men forbid their sons to play with each other. After Jeff and Porky's first attempt to fix the problem goes horribly wrong, so the boys hide in the woods in hopes that in ""saving"" them Gramps and Matt will be friends again.

With Gramps and Ellen away for the day, Jeff and Porky plan a lazy day--until an escaped circus lion invades the farm. Worse, no one will believe them when they call for help.

Jeff thinks Lassie needs a vet when her time comes, but a storm is brewing and Gramps says dogs can cope. Dr. Wilson: Frank Ferguson. Mrs. Wilson: Frances Morris.