The poem follows a strange hybrid creature, the lizard-cat, through a journey from dazzled confusion to fierce strength. At first the midday sun stuns it, and the autumn scene, with its red leaves in the Berkshire, blends with memories and sorrow. The mood is hazy and bitter, with sorrow described as something that sits in its "gall."
Then things darken. Time's "spectrum" breaks into blues and blacks, and the creature is surrounded by "mad-jawing and clawing." Yet it carries its own "fifth column of light," a hidden force that works from inside the night and floods it with thick, blood-like energy.
In the last section the sun returns, and the lizard-cat is no longer bored or overwhelmed. Its scales breathe in the fire-light, and the inferno turns into solid, lasting brightness. The poem ends on a triumphant note: the creature takes its stand "at the pinnacle of radiance." Judging by the imagery, the poem is about turning pain into resilience.