- "This is Cain and Abel stuff, I'm telling you. Question is, which one of us is gonna be wandering the Earth with a mark on his head and which one's gonna be six feet under..."
- ―Derrick McReary.
Blood Brothers is the final mission given by Francis McReary in Grand Theft Auto IV. It is unlocked after completing Derrick's final mission, "Tunnel of Death" and by completing the Gerry McReary mission, "I Need Your Clothes, Your Boots, and Your Motorcycle."
Francis sends Niko a text message telling him to meet Francis in a curb in Algonquin. Francis pulls up in a Landstalker and explains that he wants Derrick dead for "the good of the community", when in reality, Derrick is intending to leak incriminating information about Francis to a reporter, jeopardizing his career in the police force. Francis is meeting Derrick in a park in Lancet to give Niko the opportunity to kill him. Later, Derrick contacts Niko to tell him about the meeting and voices his fear that Francis wants him dead and asks Niko to go to the meeting and kill Francis before he kills him. Niko must now choose between the 2 brothers, and for the second time, kill one or the other.
In order to complete the mission the player must:
- Go to the courtyard park in Lancet
- Use the window cleaning platform, on top of the scaffolding, to get to the roof top
- Take out Derrick or Francis when ready
- Get off the roof and evacuate the area
- The cops are onto you. Lose your wanted level (If the player takes too long to escape)
Drive to the park in Lancet. After Derrick's call, Niko will contact Francis again, who gives you instructions on where to take point. Climb the scaffolding and get to the roof via the window cleaning elevator. Run up to the yellow marker. Niko will get his sniper rifle ready, now is the chance to shoot. Choose between Francis or Derrick, and kill one. If you're going to kill Derrick, make sure to call Francis while on the roof, who offers to increase the hit payment from $10,000 to $20,000. Don't think about calling Derrick because he doesn't have much money, and he doesn't have his phone on (he said his phone ran out of battery).
Whoever you kill, a cutscene will show either Derrick waking away slowly or Francis telling everyone to clear the area and fakes sadness over his brother who had just been killed, depending on who died.
After the death of one of the McReary's, immediately leave the area to finish the mission. You won't get a wanted level though, so just get in a car and drive away. You will get a wanted level (three stars) if you don't leave quickly.
After the Mission
Killing Francis McReary
If you kill Francis, you get no money, as opposed to the payment if Derrick is killed. However the next mission, Undertaker, will be much easier as the drive to the graveyard is not as long, although not by much.
Killing Derrick McReary
If you kill Derrick, you will get a large sum of money ($10,000 or $20,000 if the player calls Francis while on the rooftop to bump up the hit payment). Niko then blackmails Francis, telling him that he will no longer work for him and intends to do the same thing Derrick had planned. After a while, Francis will text Niko, giving him the temporary ability to get rid of up to 3 stars on his wanted level. This can be used until you complete the story.
- The mission may be named after the play "Blood Brothers" written by Willy Russell.
- If the player side with Francis, call Francis right before you are planning to snipe. He will offer a greater reward for Derrick's assassination.
- Do not fall of the building where the player will snipe from. If the player falls, the player will be killed, resulting in a mission faliure.
- If Niko kills both targets after the cutscene occurs, the mission will fail.
- If Niko doesn't have a Sniper Rifle, he will be instructed to collect one (with 20 bullets) from an Admiral parked near Jerkov's. If he happens to destroy the car before getting in, Niko will need to acquire a Sniper Rifle from somewhere else before continuing the mission.
- If Niko goes back down using the elevator (or a helicopter) before assassinating either targets, the mission will fail.
- Be sure not to take too long to kill one of the brothers, because doing so will fail the mission.
- Killing either Francis or Derrick not only changes the following mission, but also changes the dialogue between Niko and Gerald in I'll Take Her.
- If Francis is killed, the player can find his body at the bench, but if Derrick is killed, his body will disappear.
- If Francis is killed, his contact will remain on Niko's phone until the end of the game.
- Niko can use any weapon (except the Rocket Launcher) to assassinate Derrick, or Francis.
- In GTA V, Packie reveals that Derrick is dead. This could imply that killing Derrick is the canon choice for this mission, or that he died somewhere between 2008 and 2013. According to Rockstar, whether Derrick died in 2008 is completely up to the player. In addition, Rockstar stated that Roman's fate is completely up to the player.