At Raff's International Circus, 13 clowns pile into a tiny car, but only 12 come out alive. The thirteenth has been skewered. It turns out that he had been blackmailing several members of the circus troupe. Was the killer a fellow clown or, maybe, his wife? The circus owner or the performer with the fabulous nose? Or perhaps it was the seductive aerialist? While investigating the three-ring case, Burke performs backflips on a trampoline, comes face to face with a surly lion, and then disguises himself in the victim's clown makeup and outfit to trap the guilty party. After a wild, outrageous chase, the killer is finally cornered.