The poems in Ultramarine explore our relationship with the passage of time, both as individuals and as a species. Whether he’s examining the lost world of childhood through the long lens of memory, piecing together random fragments in the broken mosaics of his ‘tesserae’ poems, or wrestling to put the exile, isolation and vulnerability of the global pandemic into a more-than-human-world perspective, Thurston tracks “Light and occult, / the two realms we navigate,” trusting that the persistence of these “frail human signs” might still signal hope and possibility.