Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Beta Help - How to open the lev 20 door in Evelyn's Lab

I've found the hidden beach lair of Evelyn but I'm stuck a bit further since I can't open the lev 20 door (totally unbreakable) that should give access to the lab (I think).

If someone knows how to open it, please let me know.

NB : I've killed everything that moved in the hidden lair until now... was I supposed to use ruse with them to gain access ?

IIRC back towards the entrance, the Anemic Cultist should have dropped a key.

Thanks for your reply. I'll go check again (because I thought about this possibility and and already checked but obviously I missed it) when I'll return there.

-- UPDATE --
I've checked and, in my current game, couldn't find the key next to the guy killed just after the entrance. But I've loaded the previous save and did again the whole entrance discovery and, this time, the key was correctly generated.
Thanks for your help