Two episodes were written for this series but never shot...
ACES LOW: Two World War 1 air corps pilots - one French, one German - accidentally tap into the Land while dogfighting. Christa and the Porters convince both fliers to put aside their differences. However, amid efforts to return them to turn-of-the-century Europe, Kevin lets it slip that Germany will lose the war...*and* that there will be a Second World War, even more tragic than the First, two decades thereafter. The German ace decides he can win the First War, and prevent the Second, by using Shung's power-crystal...which he accordingly steals. What he doesn't know is that, if Germany does win, Tom's parents will never meet and thus he won't exist - which means that neither will Annie and Kevin!
FINE PRINT: Annie struggles with homesickness...tempered with Kevin's frustration that numerous people come and go from the Land of the Lost, yet the Porters are never among them. That's when a beautiful red-clad young woman, who calls herself Lucy, rescues the siblings from a Sleestak ambush. Lucy explains that she can send the Porters back home, provided they sign a pact with the Devil; indeed, her name turns out to be short for "Lucifer"! Annie, Kevin, and even Christa agree to Lucy's terms; yet Tom hesitates to do the same, despite Annie's speculation that the Land actually *is* Hades. Ultimately, Tom's suspicions regarding Lucy prove correct; now he must draw on his experience as a lawyer to save the souls of his kids, and of Christa.