Bismarck is unsinkagurgle?
Can someone please explain this joke to me? It was in "The Problem at the Gallows Part 1." I know the Bismarck was a German battleship used in WWII and it was considered "unsinkable" (it, along with its 'sister' Tirpitz, was the largest, most powerful, German naval menace of its time). It eventually did get sunk though. But I still don't quite get the joke.... :(
"You know the shortest joke in the world? The Bismarck is unsinkagurgle."