"Skylons"
Written by Dick Morgan
Directed by Bob Lally

At 2:32 on the DVD, the chicken on the right side of the screen is pooping!

At 2:51 on the DVD, the laughter of a stagehand can be heard as Will chases the chickens.

This is the first time we've seen a pylon since the first episode. It is shinier than the one we saw then and there are seams visible around the diamond-shaped door and elsewhere. Looks like a set piece wrapped in gold foil.

Grumpy kills Spot in this episode. After this episode the Marshalls seem to refer to any Coelophysis they see as Spot, in honor of the original, I suppose.

When Will flashes his signal mirror at the pylon, the key above the door seems to signal back. Later, when Will shines the light of the mirror on it from close range, the key falls off the pylon for some reason. These attributes of the keys are never seen again in later episodes.

The key seems to have a magnetic attraction/repulsion to the pylon.

Like Dr. Who's TARDIS, the pylon is larger on the inside than the outside.

The pylon seems to have an electrical self-defense mechanism as evidenced by the shock delivered to Grumpy when he tried to bite it.

At 13:35 on the DVD, the lightning flash reveals that there is black fabric or paper covering the open doorway of the pylon set piece.

The Marshalls considered "sky pylons", "twirling tops" and "golden streaks" before settling on "skylons" as the name for the companion objects to the pylons (and Will once refers to them as "the three musketeers").

At the very end of the episode back at High Bluff, Rick puts a rock on the fire instead of wood!