Poole carefully dons a pressure suit and boards one of the extravehicular capsules in order to step outside the ship and replace the defective part. After careful manipulation and much patience, he successfully replaces the part and returns to Discovery.
Unfortunately, not all was well. Bowman ran diagnostic tests on the AE-35 unit that Poole had replaced and reports to Poole that it is actually fully functional. Before they resolve how to handle the situation, a transmission from Earth arrives. Mission Control confirms that the AE-35 they replaced is fully functional and suggests that the problem may lie in Hal. They are to monitor Hal closely for further odd behavior. At worst, they will have to shut down Hal and hand over monitoring control of the ship to the computers at Mission Control.