Approaching darkness adds a darker feeling to the poem. It makes it feel darker and sadder about the deaths of the starfish. The word suicide in the text makes it also have a darker tone. The mood completely changes in this excerpt because of the talk of death and darkness. It sounds like in the text that the starfish(s) dies at the end, a bunch of them. The poem definitely displays a darker mood. In the excerpt together: little martyrs, soldiers, artless suicides is part of the poem that relates to "approaching darkness. " Hope this helps! :)