Elias is the traumatised son of a murdered woman, using a network of informants throughout the city to provide him with the information he and his associate need to protect people.

Harold Finch is the billionaire genius determined to avenge the people who took his friend Nathan from him, tried to kill him, and condemned his bodyguard/assassin John Reese to a life of cruelty and deprivation until Harold rescued him.

They have a grudging respect for each other, but still - they are both in each other's way.