Heywood Floyd: HAL, who the hell is sending this?
HAL 9000: I'm sorry, Dr. Floyd, I don't know.
Heywood Floyd: Well, tell whoever it is that I can't take any of this seriously unless I know who I'm talking to.
HAL 9000: Dr. Floyd?
Heywood Floyd: Yes?
HAL 9000: The response is, "I was David Bowman."
HAL 9000: Do you want me to repeat the last response?
Dr. Heywood Floyd: No, no. Tell Curnow that this is no time for jokes.
HAL 9000: Dr. Curnow is not sending the message. He is in access way two.
Dr. Heywood Floyd: Well, tell whoever it is that I can't accept that identification without proof.
HAL 9000: The response is, "I understand. It is important that you believe me. Look behind you."