Higuchi, the new Kira, is captured and the Death Note is touched by Sachiko Yagami which allows him to see Rem.  L and Light both touch it also but for Light it gives him back all of his memories.  He uses a stashed piece of the notebook in his watch to kill the new Kira and take ownership of the book once again.  With the book in their possession, the task force learn many things about how Kira killed his victims, including two additional rules added by Ryuk at Lights request which throw them off any suspicion of he and Misa being Kira.  With Misa free, Light tells her where to find the other note book and she too regains all of her memories.