Some villains are too prideful when it comes to killing off heroes, or in this case, a great mouse detective.
Like the James Bond films of the 1960s, Professor Ratigan, the world's greatest criminal mind in all of Mousedom, decides in the Disney animated classic "The Great Mouse Detective" to kill Basil of Baker Street in the nastiest way he can think of.
After Basil and his side kick Major David Q. Dawson follow the peg legged bat, Fidget, into the under belly sewer pub of the mouse world, they immediately are led into a trap in which Ratigan gets the upper hand.
However, because Ratigan has to use his "superior" intellect to out wit Basil, he cannot kill him in an easy fashion. This is where villainy comes before a fall.
Let's count the number of times Ratigan could have killed Basil my fellow interns:
(1) If he bothered to send a henchman, namely a pegged bat to snatch a toy maker, Fidget could have barged into Basil's house and gutted him with his sharp claws.
(2) Basil and Dawson are ambushed by his entire gang of ruffians and thugs in which there is no escape or way to resist because the ambush was so clever. They should have died right there!
(3) Basil gets put into a mouse trap that is cleverly set off by a string being tightened at the time of the record finishing setting off a chain reaction of nasty axes, guns, crossbows, anvil, and the so predictable mouse trap. [As a side note, cartoons or villains in general that leave the hero unsupervised tend to have their plan of execution fail. Villains please do yourself a favor and just stay put until the protagonist has their demise].
(4) In the Big Ben brawl, he pushes Basil off a cog but fails to check if Basil is actually dead which inevitably leads to his fall, literally.
Conclusion:
SPOILER ALERT: You are only a "real" genius if you can actually kill the hero. Until you do, please save the rest of this world trouble by killing your ego. Ratigan fails to kill Basil and thus he is not a genius after all.