Season 2 Episode 18TVMSHOW Not rated yet Your Rating login to see it
Lena’s ex-boyfriend, Jack Spheer, comes to National City to unveil his big breakthrough in nano-technology, which has the potential to eradicate all diseases. Lena asks Kara to attend Jack’s conference with her for support. When Kara sees Snapper in attendance she’s inspired to tap back into her reporter skills and questions Jack on his discovery, which ultimately leads to a bigger investigation that puts everyone in danger. The crossover continues on The Flash S03E08 Invasion! (II), Arrow S05E08 Invasion! (III) and DC's Legends of Tomorrow S02E07 Invasion! (IV).