What is Caliban trying to convey to Stephano and Trinculo?

PROSPERO Fury, Fury!—There, Tyrant, there. Hark, hark! Caliban, Stephano, and Trinculo are driven out Go charge my goblins that they grind their joints With dry convulsions, shorten up their sinews With agèd cramps, and more pinch-spotted make them Than pard or cat o' mountain. ARIEL      Hark, they roar. PROSPERO Let them be hunted soundly. At this hour Lie at my mercy all mine enemies. Shortly shall all my labors end, and thou Shalt have the air at freedom. For a little Follow, and do me service.