The Hobbit: 10 Dumbest Character Decisions
3. Gandalf Went Into Dol Guldur Alone
Gandalf had a great concern about the fire drake that took up residence in the Lonely Mountain so many years ago. However, there was far more on his mind than just Thorin and Smaug, one of which dragged him away from the Dwarves arguably right when they needed him most.
It was Radagast the Brown who first felt the dark and uncomfortable witchcraft of the Necromancer, and after he went to investigate, he was able to prove to Gandalf thanks to a morgul blade that there was evil afoot.
Right before entering Mirkwood, Gandalf went to seek information for himself. At first he took Radagast with him, but sent him away before entering the haunted fortress that was Dol Guldur. On his own, he was of course absolutely no match for the nine ringwraiths.
Gandalf was defeated and imprisoned quickly and easily, and thus missed his meeting with the Dwarves, was absent for their fight with Smaug and the dragon’s subsequent attack on Lake Town, and arrived at the mountain way too late to stop the Battle of the Five Armies. If it weren’t for the help of Galadriel, Elrond, and Saruman, he would never have left.