First published 1956
When identical twins Tom and Pat volunteer for a deep-space mission, only one can go. As Pat voyages light-years away, time dilation means he ages far slower than his sibling back on Earth. While Tom grows old, Pat explores the cosmos - but the brothers' fates remain inextricably linked. This timeless tale of relativity, adventure, and the human spirit will captivate readers from start to finish.
Genres: fiction, classics, adventure
Vibes: emotional, suspenseful, thought-provoking
Tropes: siblings, time-travel
Period: Future
Mass Market Paperback · Del Rey