|His name is Mudd...Harry Mudd|
Returning along with Harry Mudd were Roger C. Carmel to provide the character's voice and Stephen Kandel, writer of Mudd's previous two appearances as well as the aborted "Deep Mudd."
As "Mudd's Passion" begins, the Enterprise is on its way to the remote mining planet Motherlode, where their "old friend" Harry Mudd is attempting to sell a love potion to the miners there. Kirk and Spock take Mudd into custody and throw him in the ship's brig until they can turn him over to Federation authorities for trial. Along the way, the ship is diverted to investigate an enigmatic Class M planet orbiting a binary star.
Meanwhile, Mudd cons nurse Christine Chapel using the love potion to help him steal the nurse's Starfleet I.D. which he uses to escape the brig and steal a shuttle. Taking Christine hostage, Mudd descends to the seemingly uninhabited planet, which turns out to be inhabited by giant carnivorous rock-like creatures which attack Mudd and Christine.
Back on board ship, it turns out that, to the surprise of everyone, most especially Mudd, the darned love potion actually works. Spock falls madly in love with Christine, while the rest of the crew begins acting oddly after the potion gets into the ship's air supply through a ventilation shaft.
Kirk and the love struck Vulcan beam down to the planet to recapture Mudd and rescue Christine. Kirk distracts the giant rock creatures by feeding them the last of Mudd's love potion, allowing the foursome to escape back to the Enterprise.
Once back on the ship, Mudd goes back to the brig, while the effects of the love potion prove only temporary, leaving those affected with symptoms resembling a hangover and the side effect of temporary hatred for the former object of their drug induced affections. Oddly, Spock seems immune to this side effect, or at least able to do a better job of containing his anger than he did of hiding his amorous feelings for Chapel.
Once again, this episode proved better on rewatching than I'd originally remembered it. There are actually a couple of lines in the script that made me laugh out loud. Fred Freiberger would have hated it.
One thing in the script that surprised me was Scotty's reference to feeling like he had a hangover even though he hadn't drank any Scotch. Its certainly not the type of line you'd expect to hear in a typical Saturday morning cartoon.
Overall, "Mudd's Passion" is one of the better installments of the animated Star Trek and a fine vehicle for the return of everyone's favorite interstellar con man, Harcourt Fenton Mudd.