Bring with you the first torch of Tomb of Semerkhet up to the room with 3 ropes.
In Tomb of Semerkhet you can easily bring with you the first torch up to the Chess Board room. Lose the game to open the hole(s) on the floor. Then throw the torch into the hole and drop down. Get it again. Slide down the ramps with the torch. Just before jumping/grabbing to the alcove of Secret #3, trow the torch (pistols on/off) into the alcove. Then it's easy to have it up to the room with 3 ropes, near Secret #5. Turn on the torches on the wall... and get this (well protected) Secret. In this way you got it without the second torch, and then, from Secret #6 you can jump direcly to Secret #7 and the level exit. The picture shows Lara with both torches, for fun.