The poem begins small: an open door, a few plain things, and the idea that even simple objects can start a journey. Being shut in, it suggests, makes ordinary thresholds feel like roads. But the speaker admits that a door doesn't quite compare with what comes next, an old cellar where "we" went down and drank "fine rain." That odd phrase may mean rainwater, or wine described as rain, and either way it feels precious, almost secret.
The scene turns warm and close. People hold hands of cards, a pun on the cards in their grip and the hands joined together, and they lie together, which could mean cards laid on a table or bodies resting side by side. Then the ending cuts in: the only violin is "dead of the plague." The music is gone.
The mood is quiet, wry, and a little haunted. The speaker seems to find small comfort and play in confinement, while the silent violin reminds us what is at stake outside.