Decision

In a fog-shrouded forest, Light gives up ownership of Rem's notebook yet keeps his recollections, since he still holds Ryuk's, buried nearby. He instructs Ryuk that the phrase "get rid of it" will signal his wish to release that one too. Misa, meanwhile, wakes with her memories gone and assumes a stalker has abducted her, baffling the team because Mogi had taken her in as the second Kira suspect and she had offered no resistance. L's questioning yields nothing beyond her insistence that Light happens to be her boyfriend.

Light approaches the Task Force and proposes that he might be Kira without realizing it, citing his investigation by Raye Penber, his presence in Aoyama, his meeting with Misa, and his own stray wishes for certain people to die. Over his father's fierce objection, he asks to be locked away, and L consents. Soichiro soon requests his own cell, unwilling to let emotion cloud his judgment, and L grants it while keeping him in contact with the outside. With Light imprisoned, the executions cease and L's suspicion deepens, even as Ryuk endures the pangs of withdrawal.

After a week behind bars, Light judges the moment right and relinquishes the buried notebook; as Ryuk departs and his memories drain away, his sudden confusion only puzzles L further. The killings restart the following week at a pace that makes up for the lull, and though Soichiro is told, L withholds the development from Light, still unconvinced. Two rules surface: a death's timing and conditions can be altered but never the death itself once a name is set, and a lost or stolen notebook forfeits ownership unless reclaimed within 490 days. It aired in Japan on January 30, 2007, and in English on February 8, 2008.