Ian Quinn's Mansion is the primary residence of billionaire Ian Quinn.
Citizenship of Ian Quinn
Ian Quinn became a naturalized citizen of Malta and transferred Quinn Worldwide's activities to the country, even buying the prime minister's estate in Valletta, due to the large underground complex it had. Quinn began to plan and develop internationally illegal activities, as his status as a Maltese protected him from the interference of organizations such as S.H.I.E.L.D. One of these activities was the kidnapping of Franklin Hall, attacking the convoy transporting him to a S.H.I.E.L.D. facility.
Kidnapping of Franklin Hall
Franklin Hall was transferred to Valletta, where he reunited with Ian Quinn, responsible for his kidnapping and Hall's former colleague, and that he made another step kidnapping him after stealing his ideas and making money out of them, something that Quinn excused arguing that they both believed in the freedom of information.
Quinn couldn't pass up on the opportunity of "rescuing" Hall after intercepting a communication about his transfer, and Hall noticed how Quinn used Malta as headquarters to stay out of S.H.I.E.L.D.'s jurisdiction. Quinn revealed the true motive of Hall's presence, the discovery of Gravitonium, a substance formerly believed to be theoretical but heavily studied by Hall, that Quinn managed to find and use to power a Gravity Field Generator, one of Hall's early designs.
Quinn asked Hall to help him in the completion of a giant Gravity Field Generator using the whole cluster of Gravitonim, but Hall tried to convince Quinn that the generator was too dangerous to be used. Failing to convince him and knowing that Quinn would use the Gravitonium with or without him, Hall agreed, with the secret intention of destroying the generator and the Gravitonium.
Agent Phil Coulson and his team were tasked with the mission of rescuing Franklin Hall and, having discovered that the responsible Ian Quinn and they couldn't act as S.H.I.E.L.D. agents in Malta without breaking international law, planned a way to infiltrate Quinn's mansion, with Skye volunteering to go into the mansion using an invitation to a shareholders' meeting she hacked with her phone, as she was not a member of S.H.I.E.L.D. and could help the rescue mission.
In Malta, Coulson's Team planned the details of the infiltration mission, with Skye infiltrating a shareholder party in Valletta with the remote back-up of Leo Fitz, Jemma Simmons, and Melinda May, in order to trigger a reboot to the defensive systems that surrounded the compound, so that Agents Phil Coulson and Grant Ward could sneak inside.
During the shareholder meeting, Skye blended with the other guests, meeting architect Qasim Zaghlul, surprising her teammates with her resourcefulness, and approaching Quinn, who knew she was part of the Rising Tide and offered her a spot in his company.
Quinn delivered a speech to his shareholders praising Malta for allowing them to pursue profit and progress without the same regulations they would encounter in other countries, and how that let them achieve goals in using basic minerals, or even others like uranium or plutonium. Quinn presented Gravitonium to his shareholders, explaining the potential uses it could have.
Skye seized the opportunity to enter the mansion in order to hack into the laser fencing control system to allow Coulson and Ward entrance into the compound, as they entered Malta using a lifeboat to arrive at a nearby beach.
Quinn discovered Skye inside the mansion, and as he thought she was trying to discover some of his secrets for the Rising Tide, he tried to called the security guards to get her out. To fulfill her mission, Skye revealed that S.H.I.E.L.D. was monitoring them, and Quinn invited her to his office.
Skye cut off the communications with her teammates to gain Quinn's trust, and told him how she helped them in Los Angeles, and lied saying that she joined them with the intention of gathering inside intel. Quinn believed her story, as S.H.I.E.L.D. could have used her in order to not break international law. Skye bought enough time to find a wireless connection that allowed Fitz to deactivate the laser fencing, allowing Coulson and Ward to enter the compound at the last moment, as they were getting surrounded by Quinn's men.
Inside the compound, Coulson found Franklin Hall, who refused to escape with Coulson. Hall revealed his own plan to be kidnapped in order to destroy the Gravitonium and kill Quinn in the process, overloading the Gravity Field Generator. Coulson was knocked unconscious for a brief moment as the gravity was reversed in the room, and tried to talk down Hall and convince Hall not to destroy the generator in order to save his team.
Quinn discovered Skye's ruses and threatened her with a gun, arguing that he could have saved her from S.H.I.E.L.D., just like he did with Hall. Skye used Ward's training to take the gun and escape, but Quinn desisted chasing her after realizing the Gravitonium had begun to disrupt gravity. Quinn promptly ordered his chopper to be prepared for an evacuation, leaving Malta and his shareholders behind.
Hall was determined to sink the whole complex under the ocean, justifying himself for all the destruction Quinn caused to the world, something S.H.I.E.L.D. was also guilty, as the experimentation without thinking of the consequences was what sparked the Chitauri invasion in New York City. Coulson tried to cut off the current of the generator, but the Gravitonium continued to grow at an exponential rate. He was forced to find a catalyst to throw into the core and neutralize it. Seeing no other option, Coulson was forced to let Hall fall into the Gravitonium cluster to stop the generator and save hundreds of lives.