The Doctor stumbles forward, nearly losing his balance and then hoping on one leg to try and rid himself of his newly found reptile friend from his leg.

They made it further down the hall, when that metal-like sound made it's noise again, causing the Doctor to stop. "That was definitely mechanical in nature." He flashed his torch down the corridor they came from and saw in the distance the entrance was now blocked off.

"Alright, we definitely need to move now." Because being trapped with snakes definitely wasn't an idea of a good time.

He dashes forward with the Master with him until they found the end of the corridor with two doors on each side. "I'll open this one, you that one."