Blue Cat Blues is the 103rd and final episode of the original series of the popular show Tom and Jerry. However, this one, unlike the usual comical storylines in most episodes, is very disturbing. Because of this, you are unlikely to see this episode on TV nowadays.
The episode began with a depressed Tom sitting on railroad tracks, bent on suicide. Watching from a bridge crossing the tracks from above, Jerry is sympathetic with Tom's state, but believes that "it's better this way."
Jerry then remembers the events leading up to Tom's depression: Tom and Jerry were best friends with each other, until Tom became attracted to an unnamed female cat. Jerry, worried that Tom would be left heartbroken, tried to stop him falling in love with her but failed.
The female feline initially reciprocates Tom's feelings, until Tom's rival Butch sees her for the first time. He too, is immediately attracted to her. He grabs her and then kisses her hundreds of times. The female cat then immediately dumps Tom for Butch, possibly only due to the latter's wealth.
Tom then tries to win her back, ignoring Jerry's pleas to give her up. He first tries to win her back with flowers and perfume but to no avail. He then spends his entire life savings on a diamond ring. Unfortunately for Tom, Butch had bought her a ring with a diamond so large and shiny that it cannot be looked at without eye protection! In a last grasp attempt to win the female feline back, Tom gives himself up to slavery to buy a car. Sadly it doesn't work, as Butch owned the most expensive (and longest) car in the world.
Tom, now broken-hearted, penniless, and set for a life of slavery, tries to forget everything by drinking. He then tries to kill himself by literally letting himself go down the gutter, until Jerry, at the last second, rescues him. Tom at this point was knocked out and was only revived when he was splashed by water. He properly wished he wasn't however, when he sees that his ex-girlfriend is now Butch's wife; the pair drive past him in a car full of luggage, with a "Just Married" sign on the back.
Jerry then breaks from the sad story to think about his own girlfriend, Toots, thankful that she is faithful to him. Or so he thought. Unfortunately for Jerry, she had left him for another mouse, and had, in fact, just married him.
A now-depressed Jerry then joins Tom on the railroad tracks and both wait for an oncoming train to run them over. The sound of the whistle of an oncoming train turns louder as the cartoon ends.