Unfinished Tales - J. R. R. Tolkien [211]
But when Sauron learned of Gollum’s capture by his enemies the situation was drastically changed. When and how this happened cannot of course be known for certain. Probably long after the event. According to Aragorn Gollum was taken at nightfall on February 1st. Hoping to escape detection by any of Sauron’s spies he drove Gollum through the north end of the Emyn Muil, and crossed Anduin just above Sarn Gebir. Driftwood was often cast up there on the shoals by the east shore, and binding Gollum to a log he swam across with him, and continued his journey north by tracks as westerly as he could find, through the skirts of Fangorn, and so over Limlight, then over Nimrodel and Silverlode through the eaves of Lórien, 5 and then on, avoiding Moria and Dimrill Dale, over Gladden until he came near the Carrock. There he crossed Anduin again, with the help of the Beornings, and passed into the Forest. The whole journey, on foot, was not much short of nine hundred miles, and this Aragorn accomplished with weariness in fifty days, reaching Thranduil on the twenty-first of March. 6
It is thus most likely that the first news of Gollum would be learned by the servants of Dol Guldur after Aragorn entered the Forest; for though the power of Dol Guldur was supposed to come to an end at the Old Forest Road, its spies were many in the wood. The news evidently did not reach the Nazgûl commander of Dol Guldur for some time, and he probably did not inform Barad-dûr until he had tried to learn more of Gollum’s whereabouts. It would then no doubt be late in April before Sauron heard that Gollum had been seen again, apparently captive in the hands of a Man. This might mean little. Neither Sauron nor any of his servants yet knew of Aragorn or who he was. But evidently later (since the lands of Thranduil would now be closely watched), possibly a month later, Sauron heard the disquieting news that the Wise were aware of Gollum, and that Gandalf had passed into Thranduil’s realm.
Sauron must then have been filled with anger and alarm. He resolved to use the Ringwraiths as soon as he could, for speed rather than secrecy was now important. Hoping to alarm his enemies and disturb their counsels with the fear of war (which he did not intend to make for some time), he attacked Thranduil and Gondor at about the same time. 7 He had these two additional objects: to capture or kill Gollum, or at least to deprive his enemies of him; and to force the passage of the bridge of Osgiliath, so that the Nazgûl could cross, while testing the strength of Gondor.
In the event Gollum escaped. But the passage of the bridge was effected. The forces there used were probably much less than men in Gondor thought. In the panic of the first assault, when the Witch-king was allowed to reveal himself briefly in his full terror, 8 the Nazgûl crossed the bridge at night and dispersed northwards. Without belittling