How Gandalf Knew About His Mission to Isengard

Ever since Gandalf first heard about it from Bilbo, he was aware of the existence of the One Ring. Bilbo had revealed the ring to Gandalf, though he was not certain that it was the One Ring. However, he suspected and feared that it could very well be the infamous ring he had heard tales about during his travels with Bilbo Baggins.

Gandalf had already brought up the subject of the One Ring with Saruman, but he was met with skepticism. Saruman assured him that the ring had been washed away by the Anduin into the sea and was gone forever. Only later did we learn that Saruman had a different agenda. He had found Isildur’s remains near The Gladden Fields and was actively searching for the One Ring himself.

Saruman’s Suspicion and Intrigue

Saruman was not oblivious to Gandalf’s frequent visits to the Shire. He had become suspicious of Gandalf’s questions about the One Ring, suspecting that he knew something more. Gandalf’s inability to find the ring himself further fueled Saruman’s doubts, leading him to conclude that Gandalf must indeed know something crucial about the One Ring and his connection to Frodo Baggins's journey.

Urged by Saruman, Radagast the Brown, a friend and ally of Gandalf, was tasked with delivering a message. If he saw Gandalf, he was to urge him to travel to Isengard to seek council, as it was urgent. However, Gandalf had not yet decided on this journey. The turning point came when, while gathering news to warn Frodo to leave the Shire, he was met by Radagast. The message from Saruman had brought the urgency of the situation to light.

The Fire Test and Realization

The definitive point at which Gandalf realized the true nature of the ring came when he tested it in Frodo's fire. The reveal of the inscription on the ring solidified his suspicion. He had already known a great deal about the ring, but this crucial test in the fire provided him with the final confirmation that it was indeed the One Ring.

By identifying the ring and understanding its significance, Gandalf realized that his mission to Isengard was not just a matter of curiosity or concern over the Shire, but a quest to foil Saruman’s treacherous plans. The journey to Isengard served as a catalyst for Gandalf’s actions, exposing the truth about Saruman's deception and setting the stage for the mighty battles of the War of the Ring.

Through these events, Gandalf demonstrated his wisdom and foresight, navigating the murky waters of the One Ring's power and danger, and playing a pivotal role in the eventual defeat of Sauron and the return of the Ring to Mount Doom.