Ianto's eyes closed leaving Jack in a pool of tears with the love of his life in his arms. Jack felt his heart slowing but didn't care. Ianto had just told him that he loved him but he couldn't bring himself to say it back because he knew he was going to lose him. Jack had seconds to think about Ianto before his time was up but he had a plan. With the little strength he had left he pulled a shard of class from the 456's tank and sliced his arm and then did the same to Ianto and allowed his blood to fall into his lovers. Jack didn't have time to watch it work because his heart stopped leaving his head on Ianto's chest.
The 456, they made this happen. They tried to sacrifice hundreds of children's lives which the government helped them to do. So Jack had to fight back. He murdered his grandson to save thousands but that was to late. The building had been filled with poisonous gas which killed in seconds and Ianto had refused to leave Jack so died for him. But his last words were to be engraved on Jacks heart forever " I love you". Jack refused to say it just because he was Jack. He had to be brave and strong am some how along the way he was taught that loving was a defect. He had to hold on to that after the 456 otherwise he would not have had the courage to kill his grandson not if he wanted to save everyone. He had to be selfish. For the benefit of everyone.