The Plan
Tobi's plan is to gather all the tailed beasts in order to fuse them back into their original form, the Ten-Tails. He will then become the jinchūriki to the Ten-Tails, giving him immense power and the ability to project his Mangekyō Sharingan on to the moon. He intends to use the moon, the prison of the Ten-Tails' body, to cover the world in an "Infinite Tsukuyomi" (無限月読, Mugen Tsukuyomi), thereby letting him control every living being, creating a world in which no war or crime occurred.[1]
Part of his plan was to have Zetsu attract the attention of the five Kage at the Kage Summit and lure them to fight against Sasuke Uchiha. In doing so, Tobi hoped that the five would be weakened enough for him to take them as hostages to negotiate the capture of the Eight-Tails and Nine-Tailed Demon Fox. This, however, ended in failure, due to Sasuke exhausting himself almost to the point of death after combating the combined forces of the Fourth Raikage and his bodyguards, the Fifth Kazekage and his bodyguards, Mifune, the Fifth Mizukage and one of her bodyguards, and the Third Tsuchikage. Meanwhile, Danzō Shimura, the Candidate Sixth Hokage, escaped.
At the end of the first day of the Fourth Shinobi World War, Tobi took the Kohaku no Jōhei and Benihisago that each contained one of the Gold and Silver Brothers, and having already collected a portion of the Eight-Tails from the tentacle Sasuke captured, Tobi intends to put the plan into motion by the end of the following day