This issue is a nice, straightforward tale with a strong, otherworldly villain, and allusions to future weirdness. It’s the best of classic FF, and in context of the erratic ride of the last dozen issues, it’s nice to read a solid tale that contains a minimum of jumping around and plot contrivances. (NB: a minimum.)
The obvious big one is that the Fantastic Four just happen to vacation (in their uniforms) on the exact island in the South Pacific that happens to contain a disused and decaying spaceport and the still operational defensive Sentry that protects it.
This is the first mention of the alien super-race the “supreme” Kree. It’s a slow introduction, and reminiscent of the Inhumans’ introduction in issue 44. It works and it’s fun. The Sentry lets fall a lot of interesting facts and details about those that created him, among them the fact that no sentry unit has ever been defeated. It’s classic and classy FF fun.
Something does need to be said about over-writing, though. Over-verboseness is not the only problem here, but the scripter is actually writing time in between panels. Page 5’s last two panels flow very naturally into each other, the FF load up their ship, and then leave — so long as you don’t read them. Read the panels, and you find out that Ben is not already in the plane, he’s off writing a letter, and there is a significant gap between the two panels. It breaks the flow and is unnatural, and it isn’t the first time that the words vie to upstage the pictures. Knowing Lee and Kirby’s working method, this conflict is easily explainable, but not really understandable. Did Lee intentionally over-write, or was he just not paying that much attention?
Anyway, these pecadillos can be overlooked, and this issue easily enjoyed.