DAVE:  Open the pod bay doors, Hal. 
HAL:  I'm sorry, Dave. I'm afraid I can't do that. 
DAVE:  What's the problem? 
HAL:  l think you know what the problem is just as well as l do. 
DAVE:  What are you talking about, Hal? 
HAL:  This mission is too important for me to allow you to jeopardize it. 
DAVE:  I don;t know what you're talking about, Hal. 
HAL:  l know that you and Frank were planning to disconnect me, and I'm afraid that's 
      something I can't allow to happen. 
DAVE:  Where the hell'd you get that idea, Hal? 
HAL:  Although you took very thorough precautions in the pod against my 
      hearing you, I could see your lips move. 
DAVE:  All right, Hal. I'll go in through the emergency air lock. 
HAL:  Without your space helmet, Dave, you're going to find that rather difficult. 
DAVE:  Hal, I won't argue with you anymore. Open the doors! 
HAL:  Dave...This conversation can serve no purpose anymore. Goodbye.

  from http://www.thisdayinquotes.com/2011/04/open-pod-bay-doors-hal.html