Gandalf’s Possible Inaccuracy in the chapter “The Shadow of the Past”

[Galin]

"... there he took up again his great Ring in Barad-dur..."

Some have argued that this need not mean Sauron had left the One behind in Middle-earth, citing one definition according to the Oxford English Dictionary...

c. With special obj., implying a purpose of using in some way: as, to take up one's pen, to proceed or begin to write; to take up a book (i.e. with the purpose to read); to take up the (or one's) cross (see CROSS n. 4, 10): to take up ARMS, [etc.]

Perhaps if the emphasis is on "in Barad-dur" then the message might be that Sauron intends to rebuild a body and again mess with Eraidor and Rhovanion and so on, using his great ring, now that Numenor is no more.

Though Sauron had the One in Numenor as well... according to a letter anyway.