Unexplained money, and the seven sections that tax it whether or not anyone can say where it came from.
Sections 101 to 107 are the successors to sections 68 to 69D of the 1961 Act — unexplained credits, investments, assets, expenditure, and amounts borrowed or repaid on a hundi. The drafting change that matters is the verb: the 1961 sections said such amounts 'may be' charged or deemed, and the 2025 sections say 'shall be'. The rate and the bar on set-off and deduction are not in this chapter at all; they sit in section 195.