Problem mapping quest

[MrRalphen]

So, I'm making a little quest for my server, like a hallway of doom. You enter a tp and get teleported to a hallway full of monsters that your team has to kill to reach a tp that'll take you to the reward room. The problem is, i think this will be abused in the way that, 1 team clears the whole thingy, then all the low levels of the serv runs trough the hallway without any monsters, cuz they haven't spawned yet.
So, is there any way to make like, when 5 people entered the tp, a stone or smthng like that pops out infront of it and you have to wait for let's say 15 mins?

If you know how to, please leave a response

 

[hangnail]

if you don't want low levels to enter the quest then put up a exp door and change the action id to example:1050 for levels 50 to enter or make it higher but the 1 has to be in front all ways

repp if it helped