As evidence in the murder of the reformed Signalman leads Bruce and Terry to believe that Harvey Dent has returned and is hunting down villains and former villains, Terry goes after the Mad Hatter. While there he hears a commotion and goes after it, the assailant having cut up a nurse without killing her.
Apparently he told her to “Hush”.
Batman Beyond vs Tommy Elliot? Sounds kinda cool to me!