What's the catch

The devil visited a lawyer's office and made him an offer.

"I can arrange some things for you, " the devil said. "I'll increase your income five-fold. Your partners will love you; your clients will respect you; you'll have four months of vacation each year and live to be a hundred.

All I require in return is that your wife's soul, your children's souls, and their children's souls rot in hell for eternity¹."

The lawyer thought for a moment and asked, "What's the catch?"