Her discovery leads Leigh to the Mojave desert and an ambitious new space agency. Drawn deeper into the agency's work, she learns that the Atlantic trench is only one of several related phenomena from across the world, each piece linking up to suggest a pattern beyond human understanding. Leigh knows that to continue working with the agency will mean leaving behind her declining mother and her younger sister, and faces an impossible choice: to remain with her family, or to embark on a journey across the breadth of the cosmos.