Border Guards

"Border Guards" is a science-fiction novelette by Australian writer Greg Egan, first published in Interzone 148 in October 1999. The novelette was included in the anthologies The Year's Best Science Fiction: Seventeenth Annual Collection edited by Gardner Dozois in 2000, Year's Best SF 5 edited by David G. Hartwell in 2000 and Beyond Singularity edited by Jack Dann and Gardner Dozois. It was also published in the collection Oceanic in 2009.