Wall Around a Star
Butterflylike aliens had brought Earth into the galactic culture. But she was a poor relation, valued only for the living human bodies she rented out for whatever purpose her nonhuman customers desired.
Then Cuckoo was discovered. Millions of miles in diameter, less dense than air, it had a solid surface that was home to many races - including a species of Man. And that was odd, for Cuckoo was from another galaxy.
Suddenly, one human, a linguist, became very important. If Jen Babylon could solve the mystery of Cuckoo's records he might raise humanity's standing among the older races - but he might also save the galaxy.
Frederik Pohl
Frederik George Pohl, Jr. (1919-2013) was an American science fiction writer, editor and fan, with a career spanning over seventy years. From about 1959 until 1969, Pohl edited Galaxy magazine and its sister magazine If, winning the Hugo for if three years in a row. His writing also won him three Hugos and multiple Nebula Awards. He became a Nebula Grand Master in 1993.
Frederik Pohl used these pseudonyms: Edson McCann, Jordan Park, Elton V. Andrews, Paul Fleur, Lee Gregor, Warren F. Howard, Scott Mariner, Ernst Mason, James McCreigh, Dirk Wilson, Donald Stacy and James MacCreigh.
Saga of Cuckoo
Saga of Cuckoo consists of two primary books, and includes one additional book that complement the series but is not considered mandatory reads. The current recommended reading order for the series is provided below.