Bzz-
Robin had just stepped away from the car and had been about to remove his mask, but the ultrasound was so piercing that he covered his ears instead.
On the other side, Batgirl turned her head with a frown too.
Both of them looked at Chen Mo.
Who was this aimed at? Such a tough guess.
Chen Mo, who was supposed to be the ultrasound's primary target, glanced calmly and expressionlessly at Barbara and Dick, then at Batman in front of the Control Console.
"Turn it off. Your kids are going deaf."
The equipment stopped.
Chen Mo rolled his neck. Beneath the dark red armor, something squirmed unhappily, only for him to press it back down.
What a joke!
Never mind how long Chen Mo had been in Gotham. He was a prolific creator of Batman fanworks, for crying out loud. How could he not know this Old Bat?
When Chen Mo had gone on a rampage through Arkham and Blackgate wearing Venom, looking ready to turn dark and become a Spider-Man Who Laughs, he had already guessed Batman would pull this.
There was a small chance that, after they returned, Batman would call him over and sit down for a proper face-to-face talk, asking him to hand over Venom. Chen Mo would refuse, they would argue, and then they would reenact the classic Bat-kid runaway scene.
More likely, Batman would use the High-Frequency Ultrasound he had prepared long ago specifically for Venom to launch a sneak attack before Chen Mo could react and forcibly strip Venom off him.
Because the spider knew the bat, and the bat knew the spider too. Batman knew he probably couldn't talk Chen Mo around.
So before entering the cave, Chen Mo had told Venom to retreat into the Nanotech Armor's protective interlayer.