Nothing happens. There are no signs of movement, though you are sure if anything is down here they know you're here too from the noise you made getting in.
If the two on point show any signs of opening the first door, Gais'forth will move in front of them and cover the second and corridor. If they go to open the far one he will stay where he is and cover the near one. If they head straight down the corridor, he'll wonder what they are doing.
Gais'forth slips past the others and takes up a station equidistant between doors 2 & 3. Arrow nocked, ears keen and covering the corridor south and door 3.
The door here was once plastered shut, but has since been prised open, making it easy for you to get through. Beyond the door are several stone sarcophogai- at least 4, maybe more.