The Citadel of Chaos

You point to the base of the tentacle and cast your spell.
A puff of smoke and flash of light burst from the hole in the ground.
A shudder runs through the tentacle and, thankfully, it releases its grip.
As it retreats back into the ground,
you rub your leg to get the circulation back
and then set off towards the main entrance to the Citadel again.