nonplus (
http://definr.com/nonplus)
v : be a mystery or bewildering to: "This beats me!" "Got me--I
don't know the answer!" [syn:
perplex,
get,
puzzle,
mystify,
baffle,
beat,
bewilder,
flummox,
stupefy,
stupify,
gravel,
amaze,
dumbfound]