It should have been a straightforward expedition. As a young career palaeontologist, Nick Pyenson found himself in the Atacama desert of Chile, tasked with mapping rock layers to establish a continuous chronology that would help dating fossils found in the area. Whale fossils, Pyenson’s speciality, are rarely found complete, which is true of most fossils. So what do you do when a colleague takes you to the construction site of a new highway and shows you not one, not several, but literally dozens of complete fossil whale skeletons? It represented a treasure trove for science, but retrieving the material before the highway constructors would move in was also a daunting, labour-intensive task that could make or break careers. I almost found myself standing next to Pyenson in the dusty clearing, the Chilean sun beating down on me as he faced this dilemma. This is just one of several immersive narratives recounted in Spying on Whales, which successfully blends travelogue and popular science.