Summertide

Once every 350,000 years, the twin worlds Opal and Quake swing close enough to their sun to trigger Summertide, a Grand Conjunction that tears Quake's crust apart—and half a dozen parties risk the quakes to reach it anyway. Archaeologist Darya Lang suspects the event may finally reveal the long-vanished Builders behind the galaxy's alien artifacts, while administrator Hans Rebka, a fugitive alien duo, and a councilor hunting killers converge on Quake with very different reasons for being there. It opens the Heritage Universe with a deadline nobody can postpone.