The Doctor, realizing that these "dead" people are the embodiment of the child, tells them to go to their room and they leave.  During their escape from the hospital, the Doctor recognizes Jack's sonic weapon as one from the 51st century.  After being teleported aboard Jack's ship, the Doctor recognizes that it is a Chula warship.  He also tells Jack and Rose that the ambulance that Jack was wanting to sell, has nanites onboard that are rewriting human DNA to match the human child that was killed when it crashed.  The three are able to access the ambulance where the Doctor can rewrite the nanite programming to undo the damage.  A bomb is due to land on the crash site and, just as the nanites are reprogrammed, appears.  Jack is able to capture it in his tractor beam temporarily so that everyone can escape, healed and unscathed, including the young boy who originally died, Nancy's son.  The Doctor and Rose materialize aboard Jack's ship, now holding the bomb, just before it explodes and save him.