This is not a particularly good episode of "Star Trek: Enterprise"-- mostly because the show seems highly sensationalistic and titillating instead of being intelligently written.
When the show begins, Trip and Archer are attacked and Archer is taken prisoner by a Tellarite. It seems that the Klingons put a bounty on him after he escaped from their custody ("Judgment", episode 2, 19). Much of the episode consists of their voyage across space to meet up with the Klingons.
The other plot is a doozy that will probably appeal to very horny teenagers but is frankly very embarrassing. When T'Pol and Phlox go on a mission, some strange infection necessitates keeping themselves in isolation--but the same infection has somehow induced Pon Farr-- the Vulcan mating urge. Through most of the show, T'Pol is an incredibly frisky lady and demands the Doctor service her! And, throughout all this, she's nearly naked. This plot is in many ways a low point for the show, as it bowed to prurient content instead of something a bit more high-minded and enlightening!
The first plot isn't bad--that's why the show manages to score a 4.