Use the Rockin' Powder Infused Rocket Boots and deliver them to Hobart Grapplehammer.
You need to get those boots down into the caldera to Hobart Grapplehammer.
Now that they're infused with the leftover rockin' powder, they should have enough thrust to get you all the way there on one shot.
When you're ready, activate the boots. Don't worry, they're automatically set to land you safely.
Well there you are!
There's no time to waste, boy !
What's wrong with the actuator on the left boot?!
Upon completion of this quest you will gain: