“Obviously, I'm going to send Kira a reply! But what should I say...?”
Reversal (転倒, Tentō) is the twenty-sixth chapter of the Death Note manga series.
L elaborates on his plan further to the Kira Task Force. He doesn't want to reveal to Light Yagami the possibility that there might be a Second Kira because he wants to test him. He also wants Light to help make a fake Kira tape in order to discourage the Second Kira from committing more murders. If Light refuses then that would indicate that he is the real Kira who wants L to appear on TV and thus die.
L also points out that the deaths of passing policemen indicates that the Second Kira is capable of killing by just seeing the face of his victim, unlike the original Kira who needed both the face and the name.
Summoned by his father, Light goes to a luxury hotel where he meets the other members of the Kira Task Force, including L, Matsuda and Aizawa. L tells him that there is someone on the outside who can contact him (Watari). Light realizes that if everyone present dies, excluding himself, then the outsider will know that he is Kira.
Light is shown the evidence gathered so far and the Kira tapes. At first, he decides to let things take their course by not revealing that this may be a second Kira and gambling that L will appear on TV and die. However, he quickly realizes that this is a trap set up by L and instead openly states that this is the work of an imposter with even greater powers than the actual Kira—using the same logic and reasoning as L did.
As Soichiro breathes a sigh of relief, L tells Light that they were thinking exactly the same thing and that he needed Light to come to the same conclusions in order to convince the other detectives who were skeptical about there being two Kiras. Light then agrees to write a message, supposedly from the real Kira, to be broadcast on TV for the other Kira.
Misa Amane is eagerly watching television at her apartment when the news station announces that they must broadcast a video tape from another person claiming that he is the real Kira. The "real Kira" says that even though he is pleased that there are people willing to help him with his goals, he wants the fake Kira to discontinue the killing of innocent people or else he'll pass judgement on the imposter.
Misa sends a new video to Sakura TV which is passed on to the police and then the Kira Task Force which includes Light. The detectives watch it: The Second Kira agrees to follow Kira's requests but also wants to meet him and states the belief that Kira does not have "the Eyes". L and the other detectives wonder what that means. Light, meanwhile, grits his teeth in annoyance at the reference to the Shinigami Eyes and the fact that this is making it unnecessary for L to appear on TV and thus ruining a chance to kill him.
The Second Kira then suggests that they meet through their respective Shinigami at which point L falls off his chair in shock at the idea that such creatures exist!
The chapter title "Reversal" mainly refers to L falling out of his chair.