Set during S5: E14, 'My Bloody Valentine', when Sam is in the panic room detoxing from demon blood. Castiel makes efforts to reassure Dean, until Dean says, 'I just need to get some air.' Dean heads out to the impala, expecting to be alone until Castiel follows him out. - PS: Dean and Sam Winchester, as well as Castiel are not my original characters. Credit to Eric Kripke and many other Production and Distributor companies.