Those Vians are SO Funny!
A clear blooper (not a lot of laughing in The Empath!) from the third season show. Shatner clearly reacting to a flubbed line. The look of De Kelly' face in contrast is very entertaining! Restored from the original 35mm film as sold by Lincoln Enterprises in the 1970s..
A clapper from The Empath showing the Vians can be seen here:
And one of my all time favorite clapper / blooper shots from the same show is here: