Honey, We're Young at Heart

S2 E6: In a selfless effort to help the aging Mr. and Mrs. McGann, Wayne and Diane offer to transfer some of their youthful energy to the old couple through the Szalinski Zip Enhancer (pat. pending). The experiment, however, works a little too well. Wayne and Diane actually speed up their aging process, while Mr. and Mrs. McGann get younger by the minute. As Wayne and Diane grow older and more senile, Amy and Nick chase after the increasingly-youthful McGanns in a race against the clock to save their parents. They finally catch the evasive kid-sized couple and bring them home just in time to reverse the process.