S1E11 : The Perfect World

Soichiro has followed in the footsteps of L in risking his life to stop Kira/Light. Light, who has made the decision to do whatever it takes to create his ideal, crime-free world, decides to mobilize the police force to get rid of Mello. But Mello has also erected a scrupulous set of traps, and intends to risk everything to prove that Light is Kira!