The answer is the result of a bizarre design mistake.

During the temple stage, you probably saw that left-clicking on some locations (like the chessboard) will bring up a Grace icon so you can radio her. What the game doesn't tell you is that when you right-click somewhere during the temple stage, which brings up the game menu, the Hints icon has now been replaced by a headset icon. This can also be used to radio Grace, sometimes about the same stuff like the chessboard.

(Or not the same stuff--e.g. when you arrive in the room with the King Solomon statue, you will actually miss two points if you don't right-click and then left-click this headset icon to chat about the seal of Solomon! You won't access this chat by left-clicking on any objects and bringing up a Grace icon, like usual. Go figure...)

So the right-click menu is what you'll need to radio Grace for advice about the demon--worth 5 points according to guides I read. You might find the best time to radio her is after you've jumped up onto the tomb.

(I just uninstalled the game so I can't check, but it might also help to climb the tomb and then use the talisman to stun the demon before radioing. Of course, by that time, many gamers will naturally just use their dagger!)