The title, "Abridged," gives the poem its first trick: split it and you find "a bridge" hiding inside the word. The poem then builds on that, picturing a bridge laid over another bridge, as if the speaker is crossing something twice, or crossing a crossing. It's a small, strange image, and it suggests a mind going over the same ground again.
The speaker walks with "my accounts" settling in the chest. Accounts can mean money owed, but also the tally of a life: what's been done, what's still unresolved, what one owes other people or oneself. Judging by the wording, these aren't sharp worries. They "settle," like sediment or a heavy meal, becoming a quiet weight behind the ribs.
The mood is reflective and a little heavy, but calm. Nothing dramatic happens. The poem is short, as its title promises, yet it leaves a feeling of someone slowly working through their reckoning step by step.