This World Is Taboo: A Science Fiction, Post-1930 Classic By Murray Leinster! AAA+++

Land on Dara? One might as well commit suicide! Untouchable, like the Darans -- that's what they'd call Calhoun if he broke the quarantine. And they'd wipe him out on sight. But Dara needed him and that was the kind of challenge this Interstellar Med Serviceman would never dodge.