Clark learns that the Green Arrow (recurring guest star Justin Hartley)--whose public identity is Oliver Queen--was shot while trying to save a couple from a carjacking, but Oliver denies he was injured. However, when Oliver starts displaying erratic behavior, Clark and Chloe investigate and find out that Oliver is taking a super-drug that helps his body heal itself--but has severe side effects. Meanwhile, Lana makes a shocking discovery that will impact her relationship with Lex.