Police had been down several 'blind alleys' [=they had tried several methods that did not produce useful results] in the murder investigation before they found the evidence they needed.
I love books, so volunteering at the library is 'right up my alley'. [=('Brit') 'up my street']
A job like that would be 'right up my alley'! [=a job like that would suit me very well]
(..) I'm so sorry, my queen. He was a good man. "Barristan the Bold" they called him. He crossed a continent to serve me. He was a loyal friend. And he died in an alley, butchered by cowards who hide behind masks. We could pull back to the pyramid district, Then we clean the city out, until the rats (..)2015 TvShow: Game of Thrones Title: Kill the Boy Season: 5 Episode 5