While it is only in the chapter bearing the title that the “conspiracy” of Merry, Pippin, and Sam is at last “unmasked,” Tolkien gives his readers a number of clues as to the conspiracy’s existence along the way.
Frodo went tramping over the Shire with them; but more often he wandered by himself, and to the amazement of sensible folk he was sometimes seen far from home walking in the hills and woods under the the starlight. Merry and Pippin suspected that he visited the Elves at times, as Bilbo had done. (“The Shadow of the Past,” p. 51-2)
While at the time this may only have seemed an innocent conjecture on Merry and Pippin’s part as to whom Frodo has been visiting with in his “trampings” over the Shire, in light of the fear they later express that Frodo might “give them the slip,” we realize in hindsight that this speculation over Frodo’s encounters must have eventually had a deeper significance.
He [Frodo] looked at maps, and wondered what lay beyond their edges: maps made in the Shire showed mostly white spaces beyond its borders. He took to wandering further afield and more often by himself; and Merry and his other friends watched him anxiously. Often he was seen waking and talking with the strange wayfarers that began at this time to appear in the Shire. (“The Shadow of the Past,” 52)
Here we see Merry is more than merely curious as to whom Frodo is visiting with, but is actually “anxious” over what Frodo might be up to in his travels.
Later, at the Prancing Pony, we see an unusually and cryptically pensive Sam:
Sam sat silent and said no more. He had a good deal to think about. For one thing, there was a lot to do up in the Bag End garden, and he would have a busy day tomorrow, if the weather cleared. The grass was growing fast. But Sam had more on his mind than gardening. After a while he sighed, and got up and went out. (“The Shadow of the Past,” p. 54)
And when he goes out, we’re told:
He walked home under the early stars through Hobbiton and up the Hill, whistling softly and thoughtfully. (“The Shadow of the Past,” p. 55)
The next day, we’re given a hint at what he might have been thinking about when he is caught “eavesdropping” on Gandalf’s and Frodo’s conversation:
‘I don’t,’ said Gandalf grimly. It is some time since I last heard the sound of your shears. How long have you been eavesdropping?’
‘Eavesdropping, sir? I don’t follow you, begging your pardon. There ain’t no eaves at Bag End, and that’s a fact.’
‘Don’t be a fool! What have you heard, and why did you listen?’ Gandalf’s eyes flashed and his brows stuck out like bristles. (“The Shadow of the Past,” 72-3)
When Frodo, Pippin, and Sam at last set out from Hobbiton and stay with the Elves at Woodhall, we read:
After a while Pippin fell fast asleep, and was lifted up and borne away to a bower under the trees; there he was laid upon a soft bed and slept the rest of the night away. Sam refused to leave his master. When Pippin had gone, he came and sat curled up at Frodo’s feet, where at last he nodded and closed his eyes. Frodo remained long awake, talking with Gildor. (“Three is Company,” 92)
We’re told that Pippin fell asleep, but only that Sam “nodded and closed his eyes.” Why? Turns out, of course, that Sam was not asleep. But he gets more deceptive still:
‘It is,’ said Frodo; ‘but I thought my going was a secret known only to Gandalf and my faithful Sam.’ He looked down at Sam, who was snoring gently. (“Three is Company,” 92)
Again, we’re told that Sam is snoring, but we’re not told that he is actually sleeping.
In the next chapter, we get the following internal monologue by Frodo, with a Sam who seems to be reading his mind:
‘No! I could not!’ he [Frodo] said to himself. ‘It is one thing to take my young friends walking over the Shire with me, until we are hungry and weary, and food and bed are sweet. To take them into exile, where hunger and weariness may have no cure, is quite another – even if they are willing to come. The inheritance is mine alone. I don’t think I ought even to take Sam.’ He looked at Sam Gamgee, and discovered that Sam was watching him. (“A Short Cut to Mushrooms,” p. 95)
When Frodo asks him what he thinks of the Elves now that he has seen them, Sam reveals a far greater understanding of the significance of their journey than Frodo allows himself to let on.
‘Yes, sir. I don’t know how to say it, but after last night I feel different. I seem to see ahead, in a kind of way. I know we are going to take a very long road, into darkness; but I know I can’t turn back. It isn’t to see Elves now, nor dragons, nor mountains, that I want – I don’t rightly know what I want: but I have something to do before the end, and it lies ahead, not in the Shire. I must see it through, sir, if you understand me.’
Frodo’s response would seem to be deliberately evasive in its pretended ignorance:
‘I don’t altogether. But I understand that Gandalf chose me a good companion. I am content. We will go together.’ (“A Short Cut to Mushrooms,” p. 96-7)
Finally, at Crickhollow, when Frodo at last decides to reveal his plans to his friends, but before he has a chance to do so, we get a rather curious and unusual exchange between two characters in which Tolkien not only indicates what they have known all along, but in doing so, indicates a conspiracy that he has been faintly hinting at to us all along:
“It’s coming out in a minute,” whispered Pippin to Merry. Merry nodded. (“A Conspiracy Unmasked,” p. 113)