The Two Towers by J.R.R. Tolkien (Middle Earth #2)

The Fellowship is scattered. Some are bracing hopelessly for war against the ancient evil of Sauron. Some are contending with the treachery of the wizard Saruman. Only Frodo and Sam are left to take the accursed One Ring, ruler of all the Rings of Power, to be destroyed in Mordor, the dark realm where Sauron is supreme. Their guide is Gollum, deceitful and lust-filled, slave to the corruption of the Ring.

Paperback, 1982

Goodreads: 4.50