I don't understand.

Description: Former United Nations employee Gerry Lane traverses the world in a race against time to stop a zombie pandemic that is toppling armies and governments and threatens to destroy humanity itself. Cast: Gerry Lane: Brad Pitt Karin Lane: Mireille Enos Segen: Daniella Kertesz Captain Speke: James Badge Dale Jurgen Warmbrunn: Ludi Boeken Parajumper: Matthew Fox Thierry Umutoni: Fana Mokoena Ex-CIA Agent: David Morse Andrew Fassbach: Elyes Gabel W.H.O. Doctor: Moritz Bleibtreu Constance Lane: Sterling Jerins Rachel Lane: Abigail Hargrove Tomas: Fabrizio Guido Naval Commander: David Andrews Navy SEAL Commander: John Gordon Sinclair C130 Pilot: Grégory Fitoussi UN Delegate (as Jane Elizabeth Perry): Jane Perry UN Delegate: Mark Holden UN Delegate (as Timothy James Baerrington): Tim Berrington Russian Fighter: Konstantin Khabenskiy Ellis: Michiel Huisman Camp Humphrey's Soldier (as Mustafa Harris): Lee Nicholas Harris Camp Humphrey's Soldier: Mike Noble Tomas' Father: Ernesto Cantu Tomas' Mother (as Vicky Araico Casas): Vicky Araico Market Attacker (as Graham Anthony Hornsby): Graham Hornsby Market Attacker: Nick Bartlett Motorcycle Cop (as Kevin Kiely): Kevin Kiely Jnr Pharmacy Helper: Ruari Cannon Philadelphian Zombie: Ryen Perkins-Gangnes Thierry's Aide: Khalid Laith Israeli Camp Soldier (as Noa Paulina Bodner): Noa Bodner Israeli Camp Soldier (as Asaf Haim Ben Shimon): Assaf Ben-Shimon Israeli Camp Soldier: Shaul Ezer Israeli Camp Singer: Efrat Avni Israeli Camp Refugee: Yousef Hayyan Jubeh Argus Sergeant: Josh Wingate Argus Sailor: Troy Glasgow Argus Sailor (as Richard Thompson): Richard Thomson Technician: Mark Hampton Korean Doctor: Song Xuan Ke Korean Patient: Christian Wong Airline Pilot: Nikola Djuricko Flight Attendant: Elen Rhys Airline Passenger: Lee Colley W.H.O. Vault Zombie: Michael Jenn W.H.O. Lab Zombie: Sarah Amankwah Zombie (Cardiff sequence) (as Anna Biczok): Anna Biczik Zombie (Cardiff sequence): Jeno Radi Zombie (Cardiff sequence) (as Aniko Fulop): Enikö Fülöp Zombie (Cardiff sequence) (as Gergely Mezaros): Gergely Mészáros Zombie Cardiff sequence) (as Peter Molnar): Peter Molnár Zombie (Cardiff sequence) (as Lambert Toth): Lambert Tóth Zombie (Cardiff sequence) (as Roland Tzefetas): Roland Tzafetás Zombie (Cardiff sequence) (as Adam Zambricky): Adam Zambryzcki Aid Worker: Amanda Brown Russian Girl: Aggy K. Adams School teacher: Andrew Agnew Palestinian Woman: Lucy Aharish Opening Scene Co Pilot: Tim Ahern Zombie: Daniel Westwood Civilian: Bethany Apedaile U.S Marine Helicopter Soldier: Lee Asquith-Coe Soldier: Albert Dibben Harrison: Peter Basham Russian sniper: Péter Behan Officer Hawkins: Kingsley Ben-Adir Lobo Worker Aleftyina: Katia Bokor Refugee 3: Leroy Bonsu SWAT Officer: Jerome Boyle Office Worker: Lila Sara Tahri Briefing Room Person 5: Michael Anthony Brown Extra: Paul Mackie Cpl. Butler: Ian James Cameron BBC News Reporter (voice): Hélène Cardona U N Refugee: Martin Carroll Russian Refugee: Raun Carswell Officer 1: Joe Corrigall Plane Passenger: Salem Hanna Zombie (Glasgow sequence): Alan Del Castillo Kemi: Aren Devlin Henri: Philipp Lawrence Durand Journalist: Adam Geddes Riot Cop: Rod Glenn Connie Lane (double): Hattie Gotobed Troop Ship Freedom Fighter Amputee: Roman Green Russian Troopship: John Harding Lincoln: Mustafa Harris Navy Officer Lt Matthews: Shane Hart Teen Zombie Bait: Ryan Hartwig Alexey: Oleg Hill Special Ops Soldier: Pete Buzzsaw Holland Russian Citizen: Vera Horton Russian Soldier 1: Alex Humes Petty Officer USN: Jeremy Hurst U.S Soldier: Lewis James Self (archive footage): David Morrison Gambling Soldier: Iván Kamarás Woman on airliner: Julia Kay Ship Trooper: Michael Lanchbury Officer: John Macmillan USN ChPO Pearson: Jim Main Russian Soldier: Katrina Marston U.N. Representative: Colin Matthews American Soldier: Vander McLeod Staff Sargeant James: Eric Michels Wiles - Journalist / Zombie: Alastair Thomson Mills Scientist: Sandeep Mohan Boy Running for Supplies: Jeremiah Molina U.S. Soldier: Mark White Gerry Lane's Recruit: Kiera Morgan Putnam: Okezie Morro National Guard Soldier: Stuart Mower Zombie 1: Taylor Murphy Sean: Cristian Nicolae Looter: Santi Scinelli Garry's Recruit: Faruk Pruti Person in Briefing Room: Evelyn Rei Russian Passenger: Alma Rix Flight Deck Crew: Geoffrey Robe Specnaz: Barnabás Réti Vityok: Basher Savage Columbian Refugee: Jurgen Schwarz United Nations Security Council: Sharon Sheehan US Marine: Lew Smart Military Prisoner: Frank Soldato Person in Briefing Room 1: Aaron Tavaler Cookie Cotter: Hugh Terry Thug: Sami Tesfay Valentina: Katrina Vasilieva Parisian Zombie: Alexander Ward Russian Zombie: Paul Warren Jason: Eric West C-17 Pilot: Trevor White Family Man's Wife in Car: Gillean Young Russian Singer: Elena Zoubareva Written by: Matthew Michael Carnahan, Drew Goddard, Damon Lindelof Director: Marc Forster Release date: 21 Jun 2013 Box Office: $202,807,711