Wow after sitting here for 45 min, trying everything i can think of, looking on youtube, & in the faqs section, after I post this message I realize lets shoot the hanging one & bang it works!! To funny!
You must not have played Arkham Asylum. I seem to remember several occasions in that game having to cut ropes with Batarangs. --- You abandoned your friend to die. He's calling for you, while the children spread out his heart to the skies.