A Broken Trap
A large, broken trap lies before you. From the looks of it, the ogres have tried to repair the trap but to no avail. A hastily written note lies next to the trap, and strangely enough it details exactly what is needed to repair it: a thorium widget and some frost oil. Were the trap repaired, an ogre passing near it might get trapped, and could be avoided.
Clearly, it would seem fortuitous that very few ogres know how to read.
The thorium widget slides effortlessly into place, creating a conduit to pour the frost oil down. Once the last drops of oil have been emptied into it, the trap snaps into position.
Woe be to any unwary ogre that should just so happen to wander by!