When malfunctions start to occur on the Enterprise, the crew discover an alien ship hiding in their exhaust wake. The Xyrillians are there trying to recharge their ship to get home. The Enterprise engineer, goes over to the aliens to help them repair their ship - but unwittingly becomes pregnant in the process!! He and an alien reach into some granules which enables them to read each others minds.  Apparently they also exchanged genetic material via the granules. Trip fixes the ship which goes on it’s way before the crew realize he’s pregnant. Trip has a hard time explaining he had behaved like a perfect gentleman. A hunt for the aliens causes another encounter with the Klingons which surprisingly helps them this time.T'pol reminds them of the comrade they rescued and returned to his home planet by captain Archer. The Klingons will only let the aliens go unharmed if the Xyrillians trades them their holo-technology.