I imagine that if I were Gandalf and had just made certain of the One Ring, that I should damn well pack up Frodo that day, get Sam and haul his ass to Rivendell. That damn day. I suppose that Saruman would present a second choice, and Galadriel a third, but I would get him the hell out of the Shire, where the nearest protection is Rangers who don’t come into the Shire even when ring wraiths do. I would be months ahead of Sauron.
Presumably having arrived in Rivendell with Frodo, Sam and Aragorn, there would have been no time for the summoning of the White Council or the Council of Elrond. In any event, speed again being the best element of surprise I can muster against an unprepared and overconfident Sauron, we would set out immediately to Lothlorien with Elrond and Glorfindel and Elrond’s two sons as rounding out the party. Let’s go see Elrond’s mother-in-law. Over the pass. Which is not yet snowed in, and which Saruman doesn’t know yet to watch. I presume that at this point, I either get lucky and choose Galadriel over Saruman as the next way point, or I drop in for a surprise visit on Saruman. As far as dinner table company, I don’t yet know of his treachery, but he is seriously outnumbered and outgunned. He is either discovered and we have to wait on top for rescue, or he becomes an in-party traitor, much worse than Boromir. This is potentially quite interesting a story line. It beats killing him and fighting our way out of the angry Orcs next, and potentially still leaves us more story. Then we go to Lothlorien, or after Lothlorien, go to Orthanc.
We then have a bigger council at whichever last place we are in on. Saruman is with us. (Boromir, Gimli and Legolas are not). Gollum is following us. We know it. Saruman at some point kills Gollum, claiming it was the right thing to do. Gandalf is suspicious of Saruman and disgusted with him. However, Galadriel has not passed her test, and he worries about everyone else too, including himself. We don’t know if Saruman has his Palantir on this quest. The Lady comes on the quest with her grandsons to pester them about when she is going to be getting some great grandchildren.
So what to do? We do not need to go to Gondor at all. We decide to go East and sneak into Mordor the long way around where there are no mountains. Along the way we encounter various small parties of Orcs, and a large party that Saruman has set to ambush us. We still don’t know he is responsible, except that the Orc leader during the battle has done some activity to make Gandalf further worried about Saruman beyond the Gollum slaying.
At some point Saruman falls over and Sam helps him up. Galadriel sees the ring on Saruman’s finger and recognizes it as an attempt at a ring of power. (Remember, we are not sure that the White Council members know if Gandalf has Narya). Since many of the other party members don’t even see a ring on Saruman, they know it is a ring of power. Gandalf now demands to know which ring of power it is and how he came about it, and Saruman either says it is one of the seven, or confesses he made it (more likely) to study what Sauron might be up to. Perfectly innocent perhaps, but it alarms most of the party who start to watch Saruman and never leave him alone. Saruman always has a walking companion, and he is constantly using his voice to sooth each companion in turn.
You know, this actually is getting interesting.