The plot line involves a malfunctioning pylon that has unsettled the environmental status-quo of the Land of the Lost. And, once more, the Marshalls must re-balance Altrusia, and thus “nature” itself.
Soon, it repeats in “Blackout.”
“It’s like time is standing still,” observes Rick Marshall (Spencer Milligan).
The endless day soon begins to make the dinosaurs cranky and confused as “the day shift” runs into “the night shift,” and chaos reigns.
Then, Rick imagines Holly as a young girl of pioneer days, and Will as a World War I soldier. These hallucinations seems somewhat off-point in a story about a Land of the Lost mechanism in need of repair. We don't understand why Rick sees these particular visions, or what they mean to him. They're weird and trippy but not really organic to Marshall's character.
Once more, the environment is out of balance, and only by cooperation among diverse populations (this time human and Sleestak) can the world be healed.
I like the message a lot, I just wish it weren't repeated so frequently. It seems like there should be another way to discover the internal mechanisms of the Land of the Lost without a malfunction or crisis as the starting point.
I find the most intriguing aspect of "The Longest Day" the Library of Skulls. Here, we see a fascinating vision of Altrusia as it was before the devolution of the Sleestak people. There's a great metropolis (the Lost City in the distant past...), and one ancient skull talks in picturesque terms of a time when the Sleestak were "7,000" strong and ruled the land.
Some very interesting mythology and history to build on here...