Plot summary
As Prince J'emm 's birthday celebration approaches, M'comm plants the virus bomb underneath the event arena. Meanwhile, M'gann, Conner, and Garfield find out S'yrra is the King's murderer. S'yrra confesses to J'emm that she accidentally killed him after he forbade her to marry J'emm because of the color of her skin, and her emotional outburst caused her to lose control of her powers: her arrest saddens J'emm, who swears to help Mars forbid its caste system. The bomb is discovered due to the Legion's enemy secretly adding kryptonite to it. Conner submerges it in lava, saving everyone, but the kryptonite seemingly kills him. In a mid-credits scene, M'gann weeps at the ceremonial altar where their wedding was set to take place.
Credits
Adapted from Wikipedia contributors, List of Young Justice episodes. HTML formatting and reference markers removed.