The Interactions of the Ring-Bearers

[Mithadan]

Inziladun, way to blow up a developing theory. When you posted, I had just finished reading and re-reading several chapters of LoTR for clues, as they are well spread out. I generally do not think of looking at the Tale of Years for source material, so good catch.

So the gist of my theory was that Gollum first met Shelob at the time he exited Mordor, and that he was sent to Cirith Ungol purposefully by Sauron. Per Inzildun's cite to the Tale of Years, I appear to have been wrong (though see below) regarding when they first met. But I can confirm the balance of my theory.

In the chapter, The Black Gate is Closed, Gollum learns that Frodo and Sam intend to enter Mordor, and convinces them to avoid entering through the Black Gate, and instead use another route he had discovered. He describes:

A little path up into the mountains; and then a stair... [and] a tunnel... and a path high above the main pass.

Gollum reveals that he used this route to exit the Black Land and escape from Mordor. He denies that he was "released" with instructions. Later in the chapter Shelob's Lair, Gollum's first meeting with Shelob is described as having happened "years before" but does not discuss the specific circumstances other than his promise to bring her food.

Even later, in the chapter The Choice of Master Samwise, we have another source corroborating what Gollum said earlier. Shagrat, describing him as Shelob's "Sneak" states that Gollum had

been here before. Came out of Lugburz the first time, years ago, and we had word from High Up to let him pass. He's been up the Stairs once or twice since then...

So It appears that Gollum was allowed to exit the Dark Tower and enter Cirith Ungol. It is possible that he was led to believe that he had escaped. It is unclear whether Sauron expected that Shelob would kill Gollum. Based upon the Tale of Years entry, it seems that his exit from Mordor was not the first time that he met Shelob, though Shagrat's statement may contradict this.