The Secret Room?

[oRpheusB20]

On the second level, I'm missing the third *thing* of equipment, whatever that is, and the secret room. Pretty sure they go hand in hand.
I noticed on my second sweep that I unlocked a safe after a certain number of kills, but the problem with that is that I've trashed the place twice and can't find any sign of whatever the game considers a 'safe'. There's a briefcase, but I'm pretty sure that's not it because I can't do more than the usual pick up, look at, and throw.
So I'm probably just being dumb but wtf am I missing?

[Ephemeral]

There is an actual safe behind the bookself in the study. Once you kill 15 spiders the study open and you can throw all the books off eventually it will open. You will need to have completed 4 objectives to open the safe however