Question: when does nathan come back in gossip girl

title: Nate Archibald (Gossip Girl)
text: Nathaniel Archibald was born to Captain Howard Archibald , a successful business magnate , and Anne Vanderbilt Archibald , a member of the Vanderbilt family . On the surface , Nate seems to be the perfect `` Golden Boy '' of the Upper East Side . He is best friends with Chuck Bass , with whom he attends the elite St. Jude 's School for Boys . Nate has been with girlfriend Blair Waldorf `` since kindergarten '' . However , he secretly harbors feelings for Blair 's best friend , Serena van der Woodsen . They shared a sordid one night stand before the show began , which caused her departure to boarding school . Nate 's feelings for Blair are complicated by his ongoing infatuation with Serena and his parents ' determination to keep him on a certain path . He later goes on to attend Columbia University .