S1E5 : The Eyes of the God of Death

Misa reveals that she has fallen in love with Light and wishes to help him kill L. At the same time, L reveals to the task force that, based on the killings made at the wake of the recent broadcast, a second Kira may have appeared. L then suggests recruiting Light into the investigation team both as a way to move the investigation further and get him to possibly reveal himself as Kira.