Jacob Allen Abel (born November 18, 1987) is an American model and actor who is known for playing Adam Milligan in the CW series Supernatural (2009–10), Luke Castellan in the film adaptation of Percy Jackson & the Olympians: The Lightning Thief (2010), and its sequel, Percy Jackson: Sea of Monsters (2013), Mark James in the film adaptation of I Am Number Four (2011), and Ian O'Shea in The Host (2013).