The casting of Agnes Moorehead
in this "silent" episode was an ironic flourish by director Douglas Heyes
. At the time, Moorehead was famous for her powerful performance in the "Suspense" radio play, "Sorry, Wrong Number," an absolute classic of the medium, in which she was able terrorize audiences using only her voice. In "The Invaders" she had to use everything BUT her voice. See more
This may be attributable to artistic license, however Rod appears in his prologue on the same visual scale as the old woman. Technically as a human he should have appeared on the scale of the invaders since he appears in front of the house, however that may have revealed the plot. See more
This is one of the out-of-the-way places, the unvisited places, bleak, wasted, dying. This is a farmhouse, handmade, crude, a house without electricity or gas, a house untouched by progress. This is the woman who lives in the house, a woman who's been alone for many years, a strong, simple woman whose only problem up until this moment has been that of acquiring enough food to eat, a woman about to face terror, which is even now coming at her from - The Twilight Zone.