She has an amazing power to take the energy from other people’s heart to temporarily gain superhuman abilities. These catch the eye of Shield and Coulson is sent in to extract her.
Cava ends up on Coulson’s team–but it’s still undeterminable whether she will stay faithful to the team or take them all down with her in a mass of crazy energy.
Sound interesting? Start reading here: http://leastrandomnumber.com/agents-of-shield-at-the-heart-chapter-1/