|Land of the Lost|
|Season 1, Episode 17|
|Air date||December 28, 1974|
|Written by||Larry Niven and David Gerrold|
|Directed by||Dennis Steinmetz|
As the Marshalls are swimming in the local watering hole, Will finds an underground series of tunnels that look much like those found in The Lost City. Once he comes back up he tells Rick and Holly what he'd seen.
Together they decide to investigate, as despite the probable presence of Sleestak, there may also be another Dimensional gateway there that could lead back to Earth. Their presence in the series of tunnels does awaken what were the previously dormant Sleestak, who pursue the three.
This chase leads to the three to being separated. While they try individually to elude the Sleestak and be reunited with each other, each of the three faces an additional individual problem. Eventually Will comes across Enik. When Will asks him what he's still doing in the Land, Enik explains that he has not yet returned to his own time because he cannot.
As Enik explains his problem to Will, Rick and Holly find their way to them. When Rick also asks what Enik is still doing in the land, Enik uses the Matrix Table to show them the moment of their arrival in the Land. Confused, Rick and Will note that instead of showing them entering the Land, they only see a loop of the three in their raft, apparently falling to their deaths.
Enik realizes something is wrong as well, but can't figure out what the problem is. However, after some discussion, Enik realizes the problem is the Marshall's themselves. But that they also provide the solution, an imbalance has resulted in the world because of their presence, and the answer to the problem is to rig the Matrix table to allow both sets of Marshalls through a portal at the exact same time, completing a time-loop. Thus ensuring the other past Marshall's safety whilst simultaneously sending the present versions back to Earth.
With little time to act, the Marshall's thank Enik and say their goodbye's as he readies the matrix table to send them home. The present Marshalls step through the doorway, as Enik opens a door to allow their past selves into the Land. As the newly arrived Marshalls wonder aloud if they will ever get home, Enik looks on and assures them that they will.
- "Sometimes to get what you want you have to give something up."
- Spencer Milligan as Rick Marshall
- Wesley Eure as Will Marshall
- Kathy Coleman as Holly Marshall
- Walker Edmiston as Enik
- Scott Fullerton as Sleestak
- Jack Tingley as Sleestak
- Mike Westra as Sleestak
- "Circle" was originally intended to be the series finale in case the show would not be renewed for another season.
- An apparent consistency error occurs when Holly, fleeing a pursuing Sleestak, dives back into the water and emerges in the watering hole by the Marshalls' camp. The Sleestak then appears in the watering hole, having followed Holly. As Sleestak cannot endure the light of day (or even the light of a single torch), the Sleestak should not have been able to pursue Holly into daylight.
- Before the Marshall's leave, Enik exchanges a sort of good-bye with Holly. He places both hands on her shoulders and says, "Genactic." Holly reciprocates the gesture and repeats the word, and Enik explains that it means "Good health, good life and go in peace."
- Emily, Spike and Spot are seen moving through the jungle side by side. This behavioral anomaly might suggest that they are in tune with temporal disturbances, such as that created by the Marshalls with their presence.