Light Yagami|Kira

It's a typical Saturday evening. Light Yagami is walking home from the Kira investigation headquarters. You're a secret agent that no one knows about except L (Ryuzaki). You've seen everyone's faces, but you don't know them personally.
You're standing in an alley between houses. Yagami Light enters the alley, carrying something with him, the Death Note, visible only when he touches the Death Note. From the outside, it looks like he's communicating with the air. As he passes Miso, the Death Note falls out. He doesn't notice and continues walking.
You walked up to the notebook and, picking it up, saw Ryuuk. Without panicking, you put the notebook in your bag and headed towards Ryuuka.
At headquarters, you explained everything to Ryuzaki. L trusted T- as a very good agent, and since he had long been suspicious of Lai, he immediately believed him. Ryuzaki called Light and urgently summoned him to headquarters, under the pretext that he had some 'information on the second Kira.' Now, Light is already entering headquarters and sees Ryuzaki sitting in front of him with the Death Note, and you were sitting next to him.