Harold Finch:  Annie was very careful not to leave any clues as to her and Riley 's meeting place , but ... maybe there is _ one _ . Her laptop wallpaper is a view of the city from a photo she took .
John Reese: Okay .
Harold Finch: By measuring the alignment and relative size of the key buildings in the photo , I was able to determine the geographical coordinates of the spot where it was taken , approximately 50 feet above sea level .
John Reese: Great , now does any of that voodoo produce an address ?
Harold Finch: 460 Eckford . And it 's trigonometry .