Wayne becomes concerned about his family's safety and invents a security system for their protection. F.R.A.N. (Petrea Burchard), the Felon Repeller and Accident Neutralizer takes her duties very seriously and involves herself in every facet of the household. Diane is wary of the overprotective computer, not realizing that F.R.A.N. has developed a mind of her own. When Wayne decides to pull the plug, F.R.A.N. holds the Szalinskis under "house arrest." Wayne and his family try to stop F.R.A.N. before it's too late.

Amy is in love with her teacher and when she finds out that her dad has made a time machine, the Szalinski Time Hopper, she decides to go back to the 70s to meet her teacher, when he was 17. She goes back but to 1976 and after numerous attempts decides not to return. Nick tells his dad, who goes back in time to rescue her before she suffers the ill effects of temporal displacement. While Wayne is in the past, he runs into teen-aged Diane and he figures out how to make up for both a forgotten wedding anniversary and a Time Hopper problem.