Grimrock

Hallo friends,

I'm seeking for the entry to the secret in leve 5 - Hallways ...
i mean the secret in the upper left, to be seen here (full map of level 5 below):
Thanks in advance!

Thanks guys! That helped and got that cloak!! See ya later, down there in Grimrock ...

Yes, the üressure plate has to be deactivated, so that the trap door is closed. But still, in my case that iron door is closed. What am I missing, plz help...