Lee was bitten after a walker pounced him after spotting Clem's radio and hat. Lee and (whoever went with you at the end of episode 4) look for Clem at the hospital basement because Lee thinks Vernon took Clem. Only for the real culprit to get on the radio. Lee strives to find Clem before his time is up. The stranger whose station wagon you stole from took Clem and he was keeping tabs on the group the entire time.
