GREAT!!! But tell me, what way do I slide it, something is confusing me about what you posted, I guess I'll have to try it out and see what I can do with it, because I'm seriously stumped and getting perturbed.
OH and btw even though I haven't completed my task there in France I got a notificiation that I'd completed the Tomb challenge. HUH?
It's simple:
First move the statues so you can go into the space where the stairs are placed. If I remember correctly and understand your picture well enough; the statue on the lower half of the picture; from your sims direction, push it. Then pull the other down a square towards the direction of the lower statue.
Go into the space where the stairs have now disappeared.
Pull back the upper statue to the floor contact; and go downstairs. I believe that would be the part with some nectar racks, and several traps on the way to the other end of the room? Anyhow.
When you're done in the room, collected all your stuff etc, go back up (you won't have to go back down there, don't worry).
Push out the statue, and go wherever you'll go next. And voilą, this part of the adventure's done!
I hope it helped, unless you hadn't already figured it out yourself.