Footage of the "green for stop traffic light" scene used in the opening scene.
When they discover the frozen version of Earth, Quinn says, "We're not in Kansas anymore."
There is a shot of the four sliders silhouetted as they run from the Soviet authorities.
Arturo wishes that he was at home, drinking sake and watching Jeopardy! (1984).
Arturo (John Rhys-Davies) says that Quinn's theory on sliding is "the Holy Grail of theoretical physics"; Rhys-Davies also co-starred in "Indiana Jones and the Last Crusade," in which his character helps search for and find the Holy Grail.
Rick's more advanced alternate self shows up and gives him the missing piece to interdimensional travel.