Their latest number is someone John met before, when he was in the CIA. The man is a power hungry sadist and John had to let the man force himself on him as part of a mission. He's the victim this time around though; John doesn't tell Finch, and the number has forgotten him at first. But once it's over, he remembers and by then Finch has found out the truth too.

When the man tries to arrange to see John again, unbeknownst to him Finch goes instead and arrives just as the man finds out he's been personally and financially destroyed.

Finch lets him know this is what happens to people who hurt his friend.

Does John find out what Harold did?