With an end goal to put a positive picture on Supergirl in the wake of a genuine incident, Kara asks Winn and James to assist her with consummating her abilities, while Hank and Alex put Kara through broad physical preparing.
Supergirl S03E05, Kara and Sam investigate, discovering that all the affected children attended a public pool laced with a chemical which causes the same symptoms, and the manufacturer is owned by Morgan.
The DEO investigates the rash of dead animals; it spreads to humans, as people develop flu-like symptoms with a large scratch on their wrists. Imra believes this is the work of Pestilence, the third Worldkiller.
With Mercy and Otis having poisoned the air with Kryptonite, Alex and Lena have Kara placed into a protective suit, which filters the Kryptonite, but means Kara can’t go out and fight as it may damage the suit and kill her.