OM: Trace the Courier

[Specter]

Well, this is the second message asking about the OMs for me in the last little bit. I feel like a rookie, despite the fact Ive been lurking around here since the Thief 2 Demo came out. Anyways, here goes: (This might have been asked, but Im sure it isnt a common one) Right at the end of the level, in the cemetary, to the left of the crypt with the portal, there is a little section. I cant interact with the gates, but I wont let that stop me. Ive gotten over, and the crypt on the left is empty, only a burning torch is in there. The other one has two gold chalices, a corpse, a key (for something) and two bushes. I suppose my question is this: whats the key for? Is it just an useless addition, or is there something to this? I didnt notice the key until I placed the bushes back on the pedistals, Im not sure if that triggered the key's appearance, or if I just didnt notice it at first. Anyways, has anyone learned anything from this. I dont know what to think, Ive got all the loot, and found the only secret. Maybe this is nothing?