SureAI

WE have gotten through the Castle Gate by blowing it up and found the locked door, there is a cutscene of the mad doctor and his helper, after we are attacked Cailia suggests we search the corpses for the key.
I get the "search corpse" sign but nothing happens.
I reloaded from a save and now I don't even get the "search corpse" sign.
Is the key on one the attackers?

If I remember correctly, the key is on a corpse (a container, not a dead attacker) somewhere by the main building.

If I remember correctly, I did not find it on a corpse, it was simply lying around in the surroundings and I had a questmarker pointing to it.

thank you both
I found it easily enough thanks to your advice.
I was confused more than anything because the quest marker was on Cailia before that and I didn't check it.......