In Norway, a group of scientists led by Dr. Jones discover an abnormal dead wolf, which causes the mysterious murder of all the scientists except Jones, who is revealed to be infected by a parasite. The DEO finds out that Jones killed the other scientists. Kara gets angry with Mon-El when she finds out that he uses his powers to make money. The DEO predicts Jones' next target and Kara and J'onn attempt to stop him; but the latter drains their powers, becomes larger and stronger and escapes, leaving the pair weakened and unconscious. Alex convinces M'gann to donate blood in order to save J'onn. Jones attacks his target again; but Mon-El intervenes. With his suit ready, James arrives to fight Jones too, taking the alias "Guardian". Kara regains consciousness and attacks Jones, taking Plutonium 239, which he touches, causing him to be overloaded with energy and implode. James convinces Winn not to tell Kara about his alter ego. Mon-El is abducted by Cadmus. Meanwhile, Alex tells Kara about her feelings for Maggie. Kara encourages her to date Maggie, who reveals that she prefers just a friendship, upsetting Alex.
In Norway, a group of scientists led by Dr. Jones discover an abnormal dead wolf, which causes the mysterious murder of all the scientists except Jones, who is revealed to be infected by a parasite. The DEO finds out that Jones killed the other scientists. Kara gets angry with Mon-El when she finds out that he uses his powers to make money. The DEO predicts Jones' next target and Kara and J'onn attempt to stop him; but the latter drains their powers, becomes larger and stronger and escapes, leaving the pair weakened and unconscious. Alex convinces M'gann to donate blood in order to save J'onn. Jones attacks his target again; but Mon-El intervenes. With his suit ready, James arrives to fight Jones too, taking the alias "Guardian". Kara regains consciousness and attacks Jones, taking Plutonium 239, which he touches, causing him to be overloaded with energy and implode. James convinces Winn not to tell Kara about his alter ego. Mon-El is abducted by Cadmus. Meanwhile, Alex tells Kara about her feelings for Maggie. Kara encourages her to date Maggie, who reveals that she prefers just a friendship, upsetting Alex.