Light and Near Enter the Warehouse Expecting Opposite Checkmates
SPOILER!
Both Sides Think Mikami Will Prove Them Right
Near expects Mikami to write names in a notebook that cannot kill. Light expects Mikami to write names in the untouched
real notebook and kill everyone except him. Neither side comes to Yellow Box merely to debate the Kira case. They come expecting the notebook itself to produce the verdict.
The Breakdown
The confrontation is already decided by which notebook Mikami is carrying before he enters the room. Everything else is waiting for the test to resolve.
Mikami Writes Every Name Except Light's
SPOILER!
The Missing Name Is the Evidence
Mikami looks at the people inside the warehouse, uses the
Shinigami Eyes and writes their names. Light's name is the one he leaves out because Light is Kira. When nobody dies, the failed execution does more than defeat the plan. Mikami's list identifies the person he expected to survive.
Why it matters
Near does not need Light to confess for the notebook test to matter. The omission makes Light's relationship to
X-Kira visible in the same moment the fake notebook proves Mikami cannot kill the room.
Light Reveals Himself Before He Has Another Move
SPOILER!
The Victory He Expected Arrives as Failure
Light has spent years surviving by controlling what other people can prove. At Yellow Box, he expects the notebook to kill Near's side and begins reacting from the assumption that his victory is already guaranteed. When the deaths do not come, the confidence that made sense under his version of the plan becomes part of the collapse.
What changed
Light is no longer managing suspicion from inside the investigation. Everyone in the room is now watching Kira respond to a trap that failed.