The speaker is hunting for something across the whole universe, from the stars to the depths of hell to the corridors of heaven, only to admit at the end that the thing they're looking for is themselves. That twist is the heart of the poem. All the grand, sweeping places in the lines are really stand-ins for an inner search.
The imagery is full of opposites: quiet stars against roaring war, dark layers against light's core, hell's basement against heaven's corridor. These pairings suggest a mind pulled in every direction, calm on the surface but violent underneath. The speaker has looked high and low and found no peace in either.
The short, blunt ending, "I'm lost!", lands hard after the rhythmic, rhyming lines before it. The mood is restless and anxious, but also oddly honest. Getting lost, the poem hints, may be the first step toward admitting you don't know who you are.