When Marge and Homer leave Grampa to babysit the kids, some little green army men trigger a PTSD episode, sending the family on a journey to Grampa's past to when he was a post-war toy model.

Homer angers Marge by binging their favorite show without her, and has to pick up a new skill in order to make amends. Meanwhile, Bart prepares to compete in "Krusty's Holiday Trample".