| Season 4, Episode 17-19|
|Airdate:|| Aug 17th-18th
|List of episodes|
It is called Lost because all three episodes have the word "lost" at the beginning of their titles (See Bellow).
The three episodes have a very different plot from most episodes (excluding "Beyond Our Physical Capacities" and "Abducted!"), but a very similar one among them. In each episode, the main setting is different from the other episodes (The Earth). The main characters visit different times, different dimensions or even none of the formers, but they are just trapped inside themselves.
The three species that in one way or another cause the main characters to be trapped (or "lost") in the different settings. There are three of them: