The speaker starts with a quiet surprise: books, the things they trusted for knowledge, keep talking about endings. But the feeling that follows isn't panic about the end itself. It's a worry about what comes before it, "a great deal of evening," a long stretch of fading light with nothing much to do but wait.
The last two stanzas turn strange and a little sad. "The hooks are gone / out of the river" suggests that the means of catching anything, of pulling something up from the flow of time, has disappeared. Nothing can be fished out now. Yet the final lines don't give up completely. The speaker "expects" some new time in which to make a wish, which sounds half hopeful, half stubborn.
The mood is calm, dusky and reflective, with a thin thread of hope running through the loss. Nothing is shouted. The poem simply sits with ending and lets the feeling settle.