The Doctor caught the ivy and began to scale down like a professional rock climber. He had done similar many, many times in the past. He didn't call down to Jack as he went, he just dropped.

Once his feet were firmly on the ground, he gave Jack a wide grin.

"See? Wasn't that easy?"

Which was the point where the platform before the door started to crumble. He darted towards the Tower door and tugged it open.

"In, in!"