Irathias holds his end of the rope steady, but it's the grapple end that is slipping from the post. Aramil continues moving forward, and only narrowly manages to grab the post and hang on before the grapple slips free entirely. With one hand clinging to the post, he quickly lashes out with the other and amazingly is able to catch the rope before it swings back to the other side.
With little effort he is able to pull himself and the rope up and over the ledge and onto flat ground, and is uninjured if not a little shaken after the harrowing experience.