In the fifth verse of the poem “Design”, an invisible hand enters. The characters are “mixed” like ingredients in an evil potion. Some force making the mix is behind the scenes. The characters themselves are innocent enough, but when put together their whiteness and de rigueur shroud look are overwhelming. There is something devilish about the spider’s feast.
The “morning law” echoes the word rite, a ritual – in this case, apparently, a black mass or a Saturday of Withces. The simile on line seven is more ambiguous and more difficult to describe. The foam is white, frothy, and delicate, something found in a stream in the woods or on a beach after a wave recedes. However, in the natural world, foam can also be ugly: the foam of a polluted stream or the mouth of a mad dog. The dualism in nature, its beauty and its horror, is there in that single simile.
So far, the poem has portrayed a small, frozen scene, with the dimpled killer holding his victim as innocently as a child holds a kite. Already, Frost has hinted that nature may be, as Radcliffe squires suggest, “nothing more than an ash-white plain without love or faith or hope, where ignorant appetites cross by chance.” Now, in the last six verses of the sonnet, Frost comes out and directly establishes its theme.
What else could unite these stiff and pale things like death “but the design of darkness to horrify?” the question is clearly rhetorical; we are meant to answer, “Yes, there seems to be an evil design at work here!” I consider the penultimate line to mean: “What except a design so dark and sinister that it horrifies us?” “Pass”, by the way, is the second pun in the poem: it sounds like a mortuary cloth or a shroud. Directed carries the suggestion of a steering wheel or rudder that some pilot had to control. Like the word brought, it implies that some invisible force traced the paths of the spider, the healer, and the moth, so that they came together.