The patient's life was 'hanging by a thread'. [=the patient was very close to dying]
If you want to discuss a different subject, you should start a new 'thread'.
I lost the 'thread' of the plot long before the story ended.
(..) Travelling? Like where? Don't worry about it. Well, I retraced the ascent of The Creator when he ascended the heavens on the sacred thread of a spider's web. He enlightened, that fella, eh? And I watched Maui catch the sun, seize the day with a magical net of woven flax, (..)2014 The Dark Horse