Carpenter's film is credited on screen as based on Campbell's novella, and it is the second adaptation of it: Howard Hawks and Christian Nyby filmed it in 1951 as The Thing from Another World, which turned the creature into a humanoid and dropped the part Carpenter kept. What the 1982 film restores from the page is the premise the 1951 one abandoned:
- A thing that imitates whatever it absorbs, perfectly, so anyone at the station may already be it
- A blood test improvised on site as the only way to tell, which is the novella's centrepiece and the film's
- An Antarctic research crew with no possibility of rescue, and no authority to appeal to
The ending is Carpenter's own. Campbell lets his men win.


