The Sentry

From Author Wars - https://authorwars.com/books/the-sentry-1836475.html

Overview:

Title: The Sentry
Author: Frank Smith
Year: 2015
Type: Short Fiction

Editions/Publications:

Unknown. Asimov's Science Fiction, April-May 2015 (Unknown, Frank Smith, Dell Magazines, $7.99, 196 pages, digest, MAGAZINE)