In his dreams , Percy sees how Grover is trapped by Polyphemus , the blind cyclops that once held Odysseus captive , and is about to meet the same gruesome ending as all satyrs before him , including his father , who went searching for Pan . In his dreams , Percy sees how Grover is trapped by Polyphemus , the cyclops that once held Odysseus captive , and is about to meet the same gruesome ending as all satyrs before him who went searching for Pan and got trapped there .