Blue dude that caused the break up of Ed's marriage comes aboard as an expert to solve a generations old interspecies battle over a planet.
Only this time, instead of Kelly ending up in bed with the Blue Dude, Ed and Kelly BOTH end up in bed with the Blue Dude.
Because Blue Dude is in heat and is emitting some sort of super strong sex phermone that makes anyone who touches him fall in love with him.
Overall, and because of a number of related plot lines, it freaking PEGGED the creepy meter at a level I've not seen in a long, long time.