The poem opens with a question that sounds almost like a complaint: what kind of love is this, where we keep calling out and still aren't there? The speaker seems to be puzzling over a strange gap between wanting to reach someone and actually being present with them. "Absent" in the title sharpens that. The calling happens, but the calling person is somewhere else.
The second stanza shifts to a single image: a drum that "came beating a single stroke / out of the living." It's hard to pin down, and that's part of its effect. One sudden, lonely beat could suggest a death, a warning, or a moment that cuts through ordinary life. The poem doesn't say which. Judging by the imagery, the speaker may be thinking about loss, or about how love can fail to show up in time.
The mood is quiet, uneasy, and a little sorrowful. The short lines and sparse wording leave a lot of silence around each phrase, so the questions linger without answers.