Short story first published in Galaxy Science Fiction, December 1966.
A sequel to "How the Heroes Die". Muller, a smuggler with a cargo of precious magnetic monopoles, attempts to use Mars (the 'hole' of the title; to spacers, planets are merely gravity wells to be avoided if possible) as a means to whip his ship to a new orbit that will enable him to escape the customs authorities who are chasing him. His plan fails, and he crashlands, close to the now-abandoned base. Over the next few days, he explores the ruins and finds out the terrible story of what happened. Unfortunately, he himself suffers the same fate as the original colonists - all of which he commits to his log, which is later recovered.
The two Mars stories do belong to "Known Space" and they are specifically referred to and to some degree influence the plot of "Protector", which takes place a long time later. Also, the failure of Mars colonization as depicted here contributes to the generally-held opinion in that future history that planets (at least in the Solar System) are virtually worthless and it is asteroids which are the truly desirable real property.
Published in several collections: The Shape of Space (1969, collection), Inconstant Moon (1973, coll), Tales of Known Space: The Universe of Larry Niven (1975, collection), Three Books of Known Space (1996, coll)