Following disastrous Battle of Jabiim Obi-Wan Kenobi was presumed missed in action. Many in the Republic and Jedi Order believed him to be dead. His apprentice Anakin Skywalker, who had doubts about his master's death, was assigned temporarily under tutelage of Ki-Adi-Mundi, until the Jedi Council would make a decision about his fate as a Jedi padawan.
The future events proved however that Anakin had been right all the time. After Separatists victory on Jabiim, Kenobi and his loyal comrade-in-arms clone trooper Alpha-17 had been captured by Dark Acolyte and Confederate commander Asajj Ventress, who had subjected both of them to torture. The prisoners had managed to escape, but hot pursuit by Separatists forces, including Vulture starfighters, had damaged their stolen starship and made the escapees crashed on the Separatist-controlled planet Riflor. Some bounty hunters, very eager to earn credits, had killed Confederate soldiers to take full credit for capturing Obi-Wan and Alpha-17.
Following Battle of Varonat, in which the Jedi destroyed pirate forces, Anakin sensed that his old master was still alive, but he was in serious trouble. Ki-Adi-Mundi, convinced by fellow Jedi Masters Adi Gallia and Plo Koon, agreed to join Skywalker to track down Kenobi.
On Riflor Kenobi and Alpha-17 were fighting the bounty hunters led by Rigo. Though the fugitives were doing their best they were outnumbered and Rigo decided it was much safer to kill them than gain a bounty by capturing them. At the last moment Skywalker saved Kenobi's life by cutting off Rigo's arm. The remaining bounty hunters opened fire, but they were no match for three Jedi and one ARC trooper. The victors left the planet without alarming additional Separatist forces about their presence.
A report about Kenobi's survival boosted morale to the Jedi overwhelmed by the war. Skywalker was glad to be his padawan again. Alpha-17 said goodbye to Obi-Wan, saying he was chosen to train new clone commanders on Kamino. Anakin suggested to him to name the future clone troopers, instead of calling them by serial numbers.