Mike Stone's "Beams" is about memory slipping away and the fear of losing a loved one completely. The speaker watches the years rush past like telephone poles outside a train window, and the strong, solid memories he once had, imagined as fallen columns and broken marble, vanish just as quickly.
The empty seat across from him is the poem's central image. Dust floating in sunlight touches a wooden chair and tries to rebuild the person who used to sit there, but the effort is "feeble," and the speaker admits it fails. Even the taste of her mouth and the smell of her hair fade into the "discarded artifacts" of his mind.
The mood is quiet, lonely, and increasingly anxious. The short lines near the end, especially "I am afraid," feel bare and honest. His final fear is that when he dies, he won't even recognize her, so the loss would be complete.