The analogy with reincarnations as dominoes is interesting - when they are lined up in a row and the first domino falls on the second, and so on - that is samsara. And no questions arise when it is a closed circle, i.e., if the end is the beginning.
But if the circle is broken by Nirvana (Moksha), then a question immediately arises - one that the Buddha refused to answer: if someone who has completely paid off their karma has no more bad karma and has attained Nirvana (timelessness), then what initiates a new cycle of samsara? Where does the karma for a new life come from?
