Caractacus remained silent as Al talked; it was a situation he could not imagine. Having your sister do that to your parents...Caractacus may have disagreed with his parents, but they were still his parents. Imagining Yvonne in Lillith's place and his father in the famous Harry Potter's made him shiver slightly.
"Al," His voice was quiet, "That is unlikely. If an attempt was made at that point, both of you would probably be dead." It was harsh, but if Al kept contemplating the 'what if' scenario, it would eat him alive from the inside.
"If you keep thinking like that, keep pondering that question... we cannot logically know what would happen if things in the past unfolded differently. To keep such thoughts in ourselves, nurse them privately, it does little more than invite pain."