A bomber nicknamed Shrapnel has set his sights on Sebastian Blood, and Oliver dons his mask to protect his newfound ally. Meanwhile, Laurel investigates Sebastian's aunt who is locked up in a mental institution, and Thea learns about Roy's newfound superstrength.

When her father won't believe her accusations against Sebastian, Laurel turns to the Arrow for help. Oliver has his own doubts about Laurel, particularly when she is arrested on a charge of drug possession. Meanwhile, Roy sets out to test his new abilities but goes berserk, putting a man in the hospital.