Three short moments make up this poem, and each one moves further into darkness. First, a clock keeps ticking while the light fades. The word "methodical" matters here: time carries on in its steady, mechanical way, indifferent to what it is losing. Then shadows show up on a wall, and the stars, which we might expect to offer some comfort, never come out. The night feels total and a little eerie.
The last couplet turns from the room to the body. "Touching can make a body / understand disorder" suggests that physical contact, perhaps with another person or perhaps with one's own hands feeling through the dark, teaches something that sight and order cannot. The speaker doesn't say whether this is comforting or unsettling, and that ambiguity is the point. The title, "Ritual," hints that this is a repeated, nightly experience. The mood is quiet, uneasy and hushed, with a strange intimacy at the end.