S1·E3 Lone Gunmen

Oliver is surprised when someone shoots and kills one of his targets. As his plan is to bring people to justice vs. outright killing them, Oliver doesn't appreciate the help and searches for the gunman. He soon learns that the man, Deadshot, is taking out businessmen who are scheduled to bid at an auction on an energy company and Walter is one of the bidders. Realizing he can't protect his family and stop Deadshot at the same time, Oliver enlists Detective Lance's help, but his plan has dire consequences. Meanwhile, Laurel and Tommy get caught in an awkward situation with Oliver.