The knight develops first and decides nothing; every Indian system stays open while he must show his hand.

You'll recover it with the knight.

If White defends with the dark-squared bishop, the trap springs.

Next bishop check sets up the trap.

Forces a block; White's pieces get glued to defending the pawn.

White can't hold the pawn, and grabbing the loose bishop instead runs into mate.

The knight recaptures and quietly threatens a smothered mate.

The king is walled in by its own pieces; the pawn that could capture is pinned.