Richard Castle:  How long do you think we 'll have to stand here ?
Kate Beckett: Once Bomb Disposal finishes their sweep . We 'll know if there are any other bombs you could step on or if I 'm standing on the only _ one _ .
Richard Castle: We do n't know that you 're standing on a bomb . Could be nothing .
Kate Beckett: Did n't feel like nothing . Something gave way under my feet . Felt like a trigger plate .
Richard Castle: Could be wonky floorboard .
Kate Beckett: With a metallic click ?
Richard Castle: Loose nail . That 's how floorboards get wonky .