Gotham je v veliki nevarnosti, potem ko oblasti sestavijo skupino superzlobnežev s tajnim imenom "Samomorilska enota". Prisilijo jih, da vdrejo v arkhamsko umobolnico in od tam prinesejo tajne informacije, ki jih je ukradel Ugankar. Stvari se zasukajo še na slabše, ko eden od njih osvobodi Jokerja, ki namerava razstreliti psihiatrično bolnišnico v Arkhamu in nato še mesto Gotham. Batman mora uporabiti svojo superjunaško iznajdljivost in moč, da bi preprečil zlobne načrte Jokerja in "Samomorilske enote".
In Gotham City, the Riddler has secret information on the top secret Task Force X that he threatens to make public, but before Amanda Waller can have him killed, he is captured by Batman. Now with Riddler imprisoned in Arkham Asylum, Amanda Waller reassembles the Suicide Squad of captured supervillains with the mission to infiltrate the forensic mental hospital to retrieve Riddler's information. Led by Deadshot, this black ops team makes their way into the facility, only to face complications from within and without the team with secret agendas and double crosses all around. Meanwhile, Batman has his own concerns with an urgent search for The Joker's deadly bomb that threatens Gotham City. Eventually, all these players converge on Arkham Asylum for a showdown that few are going to escape alive.