Terrence went to take another step backwards and slipped. He caught the edge with one had, but was slipping. Now his fear of heights overpowered his fear of the vampire, and, as he looked down, he started to get very dizzy.
Flynn grabbed at Terrence's arm, and caught it just in time. He then dragged Terrence's body to the window, where he fed on him, leaving just enough so that Terrence would change to a vampire, rather than die.