No need to recap the plot. HEFILM's right: the material would have worked better in a 30-minute format. That's mainly because the one-note plot dwells on the same point, albeit with an interesting undercurrent. Middle-age Kennedy wants to join his bikini cutie and the Gidget beach crowd. On the other hand, dour wife Thaxter just wants to go home, back east. The producers knew what they were doing when they hired two of the best actors in the business-- movie vets Kennedy and Thaxter. They manage to maintain interest throughout, despite the often redundant narrative.
One interesting feature is trying to figure out Kennedy's motives. He treats Thaxter callously, but seemingly won't let her go. So why not just divorce her and then join the Frankie and Annette crowd. Then too, what is that hole in the cellar intended for. Is he acting on impulse when wielding that shovel or has he planned this all along. I'm not sure whether this undercurrent of ambiguity is intentional or not. Then again, maybe I missed something. Anyhow, it's an exotic treat watching one of Hollywood's best play a balding aerobic wannabe.