Eva Belyakov was sought out by the Inhumans and chosen for Terrigenesis. After going through the Terrigen Mist, Eva developed superhuman strength. Eva later gave birth to a daughter named Katya, and attempted to have her go through the transformation as well. However, due to Katya displaying several signs of psychopathic schizophrenia, she was denied the chance by Jiaying. Outraged, Eva stole a mass of Terrigen Crystals and used them to put Katya through Terrigenesis, despite not having gone through the mental preparation that most Inhumans did. Through her gift, she was able to feel the emotions of other humans though a single touch, and also control them.
S.H.I.E.L.D. took notice of Eva Belyakov's activities and tracked her down to Manama, Bahrain. A team led by Agents Phil Coulson and Melinda May was dispatched to analyze Belyakov for the Index; they were unaware of her daughter's involvement or powers. Eva and Katya assumed control of a group of gangsters and held the entire S.H.I.E.L.D. team, minus Coulson and May, hostage within a warehouse.
May ventured into the warehouse alone and crossed off the controlled gangsters and Eva. Katya revealed herself to May and nearly used her powers to kill the subjugated S.H.I.E.L.D. team, forcing May to kill her. For her role in saving them, the S.H.I.E.L.D. team gave May the nickname "The Cavalry", a moniker she grew to despise.
Melinda May became emotionally and psychologically scarred by the incident. She became withdrawn from her husband Andrew Garner and eventually, they divorced. May no longer wanted to be a field agent and opted to be transferred to desk duty and administrative work. Phil Coulson attempted to help his friend with her emotional issues.
The Inhumans became less trusting of Humans and passed on the story of how a human killed Eva Belyakov and her daughter. However, their telling of the incident made Melinda May the antagonist and S.H.I.E.L.D. an evil organization to be feared.