The goblins cure the Buffoon's possession, then follow him to the underworld using magic water from Tazaar's lab.
Get a Mouse
Have
Fingus stand on the eyeball in the bottom right of the
screen.
Have 
Winkle check on the "!!!", which is in the bottom-left
skull that is above the big rock,
and to the right of the yellow eye.
Fingus will get launched up where the mouse is. Get the
mouse. Have Fingus walk to the
right side of the skull he's standing on and he will go back down below.
Free the Buffoon
Have Winkle stand to the right of
the mud that is near the
bottom-left of the screen. It's to the right of a hole in the ground.
Have Fingus use the mouse on the mud, then
have Winkle jump on the crocodile,
and quickly
have Winkle use the boomerang on the in the ceiling near Amoniak while Amoniak is reaching
out. If you do it quickly enough, a tooth will stab Amoniak's hand, and
The Buffoon will fall.
Quickly
have Winkle check the "!!!", which is in the bottom-left
skull that is above the big rock,
and to the right of the yellow eye.
The Buffoon is now free.
Leave the Underworld
Have Fingus use the wet sponge on the rock.
Have The Buffoon stand on the eyeball in
the bottom right of the screen. Have Winkle check on the "!!!"
again.
Have Fingus use
the pencil on the rock, then have
Winkle click on the handle to open the door.
Congratulations! You won!