Hiro: It's over, Krei.
[Without his mask, Yokai stands up and turns around to Hiro, revealing he is Callaghan]
Hiro: Pro... Professor Callaghan? The explosion... you died.
Robert Callaghan: No. I had your microbots.
[a flashback shows Callaghan using Hiro's microbots to protect himself from the fire earlier in the film]
Hiro: But... Tadashi... You just let him die...
Robert Callaghan: Give me the mask, Hiro.
Hiro: He went in there and saved you...!
Robert Callaghan: That was his mistake!
[Baymax then comes over to Hiro, who is betrayed and angry]
Hiro: Baymax... destroy.
Baymax: My programming prevents me from injuring a human being.
Hiro: Not anymore.
[Hiro opens Baymax's cartridge, removing Tadashi's health care cartridge chip]
Baymax: Hiro, this is not what...
[Hiro slams his fist on the cartridge, leaving his own destructive cartridge chip in his system, making him rogue]
Hiro: Do it, Baymax! Destroy him!