Not to be confused with team member Mack from Series 2, Agent Mack was tasked with transporting Dr Franklin Hall to a secure location when his truck was lifted into of the air by an unseen force. Mack survived the attack and reported the incident to Coulson. (Nice to see the ‘logistics division’ side if SHIELD in action!)
Dr Franklin Hall
A brilliant scientist known for his work on the theoretical substance of Gravitonium. When the substance was discovered by Ian Quinn he allowed himself to be captured so he could destroy it, keeping it out of the hands of people who would use it for harm. To prevent the loss of life that would result Coulson dropped Hall into the substance, stabilising it. Hall however, stayed alive, merged with the substance.
The founder of mining corporation Quinn Worldwide the billionaire lived off exploiting the Earth for its riches. He became a thorn in SHIELD’s side after clashing with them over Gravitonium. He manipulated Academy students into attacking their teachers and even shot Skye when he allied himself with the Clairvoyant. After being imprisoned in the Fridge he was released by Garrett and given his Gravitonium back as reward. He remains at large.
Franklin Hall, later known as Graviton, was a theoretical physicist. A freak accident give him the ability to manipulate gravity and set him on the path of the villain, often clashing with the Avengers. We’ll have to wait and see what the fate of Hall will be in the show