 The story finishes with a brief epilogue that explains O'Neil's new job analyzing "Water X", a German expedition's "accidental" destruction of Incan ruins, and Schutz's comfortable life in Germany, where he has a new identity as a professor and his biochemical research is progressing well.As in O'Brien's "Z for Zachariah", the geographical setting is unclear and largely fictitious.Events take place mainly at Seneca Lake, in the countryside about 20 miles from Washington DC.