"With the alien menace poised to overthrow the galaxy a lone group of combateers is all that that stands between them and total annihilation. When one of their number is kidnapped by the aliens and their plans thwarted, the group must decide whether to mount a rescue and risk losing the war, or sacrifice her for the greater good of humankind…"
You can download the story from this website.
Whereas Status Quo and Mutabilis are set in the years 3138 and 3140 respectively, Finis covers the years 3149-3151, according to Selezen’s excellent Oolite timeline. For reference, Elite is assumed to have been set in the year 3125, and Oolite in the year 3142.