I realize that this was a decision by the writers to help drive the story forward, but still the question begs asking.
McCoy said he needed Khan's blood in order to save Kirk, obviously because of its special properties. However, he already defrosted another of Khan's crew, and put him/her into an induced coma in order to use the cryotube to preserve Kirk. Why not use the blood from that crew member, as opposed to waiting for Spock to get Khan back to the ship? The blood from the crew member should have the same properties as Khan, unless McCoy made the decision to go with a known factor in Khan's blood, instead of an unknown in another crew member? – The preceding unsigned comment was added by FleetMedic87 (talk • contribs).