With Lily having left for San Francisco to find herself, and Ted and Robin finally getting together, the summer kicks off with Marshall depressed over the breakup.
Ted, Barney and Robin come to his aide by getting him out of the apartment for different activities, but just as Marshall is starting to cheer up he gets Lily's bank statement that shows her last charge was for a hotel in New York; Lily is back in town.
After calling Lily's hotel and hearing a guy answer, Marshall, against his friends' advice, goes to the hotel, only to find Lily is not in town and the guy who answered the phone is an identity thief who stole Lily's credit card. After an entire summer without hearing from Lily, Marshall starts to move on.