Anakin will fight Obi-Wan and fall into some type of (lava) pit. Beliving Anakin has died, Obi-Wan reports back to the jedi council. Palptine some how had alrdy gotten to Anakin to have seduced him to the Dark side of the force, why else would Anakin be fighting Obi-Wan and its not over Padames Death. Reason 1 both Anakin and Palptine dont know that Padame was pregnant with twins(rember yoda and Obi-Wan took them to hide from the EMperor and Vader because IF they knew they would be a threat to them so they didnt know. I think Anakin left Padme went on a mission to save Obi-Wan only it was a TRAP like in ESB and Anakin turns to the darkside not knowing that Padame was pregnant with twins. So the ? is how did Palptine get Anakin to turn and what caused Anakin to turn on Obi-WAN.
lordvader:
I read anakin turns on Obi-Wan because there is a crystal that is very powerful and very evil and anakin finds it and obi-wan confronts him and the fight,(it's on some kind of volcano). obi-wan uses the force and the lightsaber comes out of anakins hand and he tries to catch it and loses his footing and falls into the lava.Palpatine brings him back to life.