"O-Ed Eleven" is the 18th episode of Season 3 and the 70th episode of Ed, Edd n Eddy. In this episode, the Eds find a treasure map in Eddy's Brother's room and set out to find the supposed treasure where the X marks the spot.
Eddy's always been a bit of a tease and today is no exception as he taunts his friends about possibly visiting his somewhat legendary older brother's bedroom. This time around though, there seems to be no catch as Eddy really does come up with the goods and the three awe-struck Eds soon find themselves standing in the suburban equivalent of Eldorado! It seems Eddy's brother was one unique character if the room decor is anything to go by! In the midst of his admiration clumsy Ed somehow manages to break a winner's trophy but Eddy's frustration soon turns to delight as a map falls out of the trophy and he realizes it's the map that leads to his brother's buried treasure. Unfortunately, the map is too unique for any of the Eds to decipher for the moment and there is not even some kind of marking that points to where the treasure is. Edd declares he will take the map but it will take some time for him to decipher it. He tells the other Eds to meet him at his house in an hour. After Edd leaves Eddy asks Ed what are they supposed to do for an hour. Ed says he has an elastic with him, but Eddy does not care. While Eddy has his back turned, Ed stretches the elastic before letting it go which causes it to hit Eddy right when the scene fades to black.
An hour later, Eddy and Ed high-tail it back to his house to see what he's made of the map. Eddy, instead of knocking, then pummels Edd's door with a shovel. Edd answers and questions Eddy why he did that. Eddy and Ed want answers about the map, but Edd guiltily confesses that the logic behind this one is far beyond his range of understanding. Eddy angrily states to Edd he is supposed to be the smart one. Ed then suddenly has an idea and states "I think I just thunk!". Edd questions Edd if that was English, but Ed then grabs Eddy and places him on the projection of the map stating to Edd that is X marks the spot.
Edd then observes what Ed did and soon realizes that Ed used Eddy's pencil-drawn ear as the "X" for the map. Edd is shocked that he was able to figure it out and asks how he did it. Ed says that it is a brother thing. Edd compliments Ed on how nicely put that was and Eddy then scoffs it off by saying "Oh brother!" to this. Edd then places a map of the Cul-de-Sac over Eddy's map to deduce where in the Cul-de-Sac the treasure is. Eddy tells him to hurry up as he is starting to see spots. Edd declares he found the place they need to find, which Eddy is happy to hear, but Edd soon sees it is not good and very risky. Edd then takes a file out of his file cabinet and states to Eddy according to his calculations, Eddy's brother's Treasure lies deep within the confines of the trailer park. He then slams down the file onto the table revealing it is the Kanker Sisters' file and that the treasure is hidden within their trailer somewhere. Eddy slams his fists down on the file and states angrily that his brother was a wiz at ticking him off.
A new strategy is called for. The Eds, poorly disguised as workmen, pretend to be working on a problem in the Kankers' drains in order to remove any suspicions on them and the girls seem satisfied with their explanation (after all workmen can be so cute). After the Kankers leave back into their trailer, Edd analyzes the map again and says that if his calculations are correct the treasure should be underneath the Kankers' trailer. As Edd and Eddy look under the latter says they should start digging, but one quick glance under the trailer is enough to convince both of them that this is a job for the Lumpy One and after a good greasing with butter he's soon busy digging and it's not long before he strikes gold in the form of an old suitcase. Eddy knows this is it but unfortunately for the boys, right in the midst of their celebrations, they realize that they have emerged through the Kankers' bathroom floor and the girls are all ready to clean up as well as pucker up. What's worse is that the suitcase belongs to them (and only filled with wishbones for some reason). Ed asks his friends what they should do now, as Edd realizes the only way out of this is to bribe the Kankers with 50 cents from each of them, this idea terrifies Eddy.
With the help of fifty cents apiece, Edd and Ed buy their way to freedom while Eddy, too stingy to cough up the cash, is left with the Kankers. Eddy tries to escape but is pulled back in the trailer by Lee. Edd thinks he should have brought more coins with him, but Ed tells him he did the brotherly thing as they walk out of the Trailer Park. Edd asks does he really think so, though Ed just responds with "Think what, Double D?" as they leave the trailer shakes with Eddy screaming for help.
When Eddy looks at the map and proclaims his excitement, the red stripe on his shirt turns yellow in between several frames.
In Edd's file cabinet, no Kankers folder can be seen, yet Edd retrieves one.
The title of the episode is a reference to the 1960 film Ocean's 11.