Enter, stranger, but take heed
Of what awaits the sin of greed,
For those who take, but do not earn,
Must pay most dearly in their turn.
So if you seek beneath our floors
A treasure that was never yours,
Thief, you have been warned, beware
Of finding more than treasure there.
(from Harry Potter and the Sorcerer's Stone)
What does ‘in their turn’ mean?
(It seems like ‘when their turn comes’. But there are dragons and traps beneath the bank’s floors, so as soon as they try and rob something they would be snapped away or trapped. That is, there would be no time lagging. So I suspect there might be some other meaning for ‘in their turn’.)