[Gordis]

Hello, I have just registered, though I have been reading threads on this forum occasionally. The present subject seems very interesting to me. I have been recently discussing it on another forum, so I have decided to post my 2 cents here as well.

To begin with: how do the nazgul sense the Ring? It seems reasonable to suppose that the ring emits some signal (an Osanwe-kenta signal, most likely) that the nazgul are able to detect. The nazgul have to "tune" to the Ring's signal to find it.

The question is whether the Ring emits its signal all the time, or only when it "knows" that the target (a nazgul) is nearby? And if the latter is true, then how can the Ring "know" it?

I don't think the Ring had any usual senses: sight, hearing, smell etc. More likely, it could only process the feelings of its current holder - Frodo. So when Frodo saw the nazgul or knew the nazgul are (or might be) nearby, he became frightened and the Ring sensed his thoughts and feelings and started to emit its signal.

When Frodo was completely unaware of the danger, even when a nazgul was really quite near, then the Ring couldn't sense the nazgul either and didn't emit its signal.

That might explain the incidents with the Gaffer (Frodo was not yet frightened at all, he even considered revealing himself to the stranger) and on the road in the Shire (there Frodo was only slightly frightened and not yet quite sure of what, and the nazgul stopped, also feeling something - but not yet sure what exactly, maybe he only smelled some hobbit flesh nearby).

The following night, Frodo was already quite frightened when he saw the nazgul, so the Ring's signal was stronger and the nazgul was much more "tuned" to the signal - he dismounted and went in the right direction. Also it has happened at night, when nazgul were more powerful. But for the Elves, Khamul would have found the Ring.

Frodo was aware of the pursuit and quite frightened all the way to the Ferry - and Khamul sensed the Ring all the time, and missed the hobbit by mere minutes:
" As soon as the Elves depart [Khamul] renews his hunt, and reaching the ridge above Woodhall is aware that the Ring has been there. Failing to find the Bearer and feeling that he is drawing away, he summons [his companion] by cries. [He] is aware of the general direction that the Ring has taken, but not knowing of Frodo's rest in the wood, and believing him to have made straight eastwards, he and [his companion] ride over the fields. They visit Maggot while Frodo is still under the trees. [Khamul] then makes a mistake (probably because he imagines the Ringbearer as some mighty man, strong and swift): he does not look near the farm, but sends [his companion] down Causeway towards Overbourn, while he goes north along it towards the Bridge. They tryst to return and meet one another at night; but do so just too late. Frodo crosses by ferry just before [Khamul] arrives. [His companion] joins him soon after. [Khamul] is now well aware that the Ring has crossed the river; but the river is a barrier to his sense of its movement." - Marquette MSS 4/2/36 (The Hunt for the Ring) published in Wayne G. Hammond and Christina Scull, The Lord of the Rings: A Reader's Companion p.116.

In the Prancing Pony Frodo was peacefully sleeping through most of the attack, I believe, waking only at the end of it - so the Ring should have been "silent". Thus the two nazgul who directed (or perpetrated) the sack of the hobbit-sized room in the Prancing Pony couldn't even tell that the Ring was in the same building, but upstairs.

The problem of the nazgul was that only the Witch-King and Khamul could sense the Ring really well. And neither of them was in Bree while the hobbits were there. The WK was still at Andrath and Khamul was at Crickhollow. The rest of the nazgul were just... well...not too good to put it mildly.
The two in Bree were especially bad: they had almost captured Merry, but panicked when Nob came shouting with a lantern... Pitiful indeed. Also, finding nothing at the Pony, the two nazgul got upset and went south to Andrath to report to the WK - leaving Bree and the East Road unguarded. That's how they lost the trail of the hobbits between Bree and Weathertop.

After that, the Ring, feeling Frodo's fear, must have been emitting its signal almost constantly, and indeed as we can see in the "Hunt for the Ring", published in the Reader's Companion: "But [the Witch-king and Khamûl] remain watching Weathertop. Thus they become aware of the approach of Frodo on Oct. 5." And that is one day before Frodo actually reached Weathertop! Not bad...

Unfortunately, the incidents that happened later (Emyn Muil, Dead Marches), are more difficult to explain. Well, perhaps there were lesser nazgul involved, whose ability to sense the Ring was no match for the WK's and Khamul's. Also, they were not expecting to sense the Ring at all, were not "listening" to its signal.

As for the incident in the Morgul Vale, I think it proves my theory.
First Frodo sees the WK, recognizes him and gets frightened. (Here the Ring likely "goes off like a fire alarm". Then and only then the WK senses the signal and stops. (Note that the WK had time to ride from the Gates of Minas Morgul all the way down to the Bridge before he felt anything - because Frodo was unaware of him and the Ring was not emitting).
'Even as these thoughts pierced [Frodo] with dread and held him bound as with a spell, the Rider halted suddenly, right before the entrance of the bridge, and behind him all the host stood still"

The Wk stops and tries to locate the source of the signal. Then the Ring "asks" to be put on. Frodo almost complies. But then Frodo finds Galadriel's Phial and gets shielded: "As he touched it, for a while all thought of the Ring was banished from his mind. He sighed and bent his head."
Likely, as Frodo's mind becomes blank, the Ring's signal stops and the WK looses it. The Morgul Lord is in a hurry and has no time to investigate the matter - but for the war, the WK wouldn't have been deterred so easily. He has sensed the Ring all right.

Does it fit?