Elizabeth Bennet and her four sisters, Jane, Mary, Kitty and Lydia, live at the countryside estate of Longbourn with their parents. Mr. Bennet oversees his daughters’ martial arts and weaponry training, as the Bennets have taken a blood oath to defend the Crown against the rising plague of zombies, which has afflicted England for the last 55 years. Mrs. Bennet, on the other hand, cares nothing for fighting and wishes only to find wealthy husbands for her daughters.
When Mrs. Bennet learns that wealthy and eligible Charles Bingley has bought a nearby estate, she schemes for her daughters to meet him at the first public ball he attends. At the ball, Mr. Bingley turns out to be the perfect gentleman and an attraction develops between Bingley and Jane. Bingley’s friend, renowned and arrogant zombie hunter Fitzwilliam Darcy, insults Elizabeth and soon gains the reputation of being proud and unable to be pleased. A zombie attack breaks out at the ball, but the Bennet sisters use their considerable skills to defend the event.
When the local militia arrives to exhume and burn dead bodies, Elizabeth becomes acquainted with one of the soldiers, George Wickham, who tells her that Darcy is a cruel man who cheated him out of his inheritance. The two have known each other since childhood but are not friends.
A distant relative of the Bennets and heir to Longbourn, Mr. Collins visits and tells the family that his benefactor, legendary zombie hunter Lady Catherine de Bourgh, has encouraged him to find a wife. Collins’ parsonage abuts Lady Catherine’s estate of Rosings Park. He sets his sights on Jane, but when Mrs. Bennet tells him that Jane is practically engaged to Bingley, Collins turns his attentions to Elizabeth. When Elizabeth rebuffs him, her friend Charlotte uses the opportunity to pursue Collins. He proposes to Charlotte and she accepts. Elizabeth is shocked that her friend would marry Collins, but Charlotte confesses to Elizabeth that she has been bitten and infected by a zombie and wants to marry and enjoy the short time she has left before she turns.
Bingley’s sister Caroline invites Jane to dinner at Netherfield Park. Jane gets caught in the rain on the way there and becomes so ill that she is unable to travel back home. Elizabeth goes to care for Jane and interacts more with Darcy, who begins to act less cold toward her. Jane recovers, and Bingley holds a private ball at Netherfield. At the ball, Elizabeth is surprised when Darcy asks her to dance.
Despite a zombie attack at the ball that kills the kitchen staff, Mrs. Bennet believes the event to be a smashing success and expects Bingley will propose to Jane. Instead, the Bennets are shocked to learn that Bingley and his companions have left Netherfield and have returned to London.
After the heartbreak, Jane goes to London to visit her aunt and uncle, hoping to see Bingley while she is there. Elizabeth goes to visit newlywed Charlotte, knowing this will be the last time she sees her friend before Charlotte transforms.
Elizabeth is saddened to see that Charlotte’s condition is much deteriorated. While Elizabeth is in Kent, Darcy and his cousin, Colonel Fitzwilliam visit their aunt, Lady Catherine, at Rosings Park. Elizabeth becomes furious when Colonel Fitzwilliam reveals that Darcy deliberately plotted to separate Bingley and Jane. She vows to kill Darcy for the slight and plans to do so when he unexpectedly stops by the Collins’ cottage for a visit. Before Elizabeth can behead Darcy with her katana, he surprises her by proposing marriage. Elizabeth confronts Darcy, and when he doesn’t deny her accusations, she viciously attacks him, leaving Darcy wounded. He escapes. The next day, Darcy writes her a long letter explaining his actions and then leaves.
In the letter, Darcy tells Elizabeth that he separated Bingley and Jane because he thought her so sick that she surely had contracted the zombie plague. He didn’t want his friend falling in love with a woman who would soon need to be beheaded. He also thought Jane to be indifferent to Bingley. As for Wickham, he explained that the man schemed to elope with Georgiana, Darcy’s then 15-year-old sister, in order to get her inheritance.
Elizabeth sees just how wrongly she judged Darcy and is deeply ashamed. After she says her final goodbyes to Charlotte, Elizabeth returns to Longbourn, saddened for both herself and for Jane, who returns from London, having not seen Bingley while there.
Elizabeth goes on a trip around the country with her uncle and aunt (Mr. and Mrs. Gardiner). While they run into a few zombies, it’s nothing Elizabeth can’t handle. They stop at Pemberley, Darcy’s estate, and while touring the grounds, the group is attacked by a large hoard of zombies. Elizabeth is without her sword, but she uses a branch to fight them off before Darcy arrives and intervenes with his musket.
The reunion is awkward, and Elizabeth notices how much Darcy’s attitude and demeanor have changed. He is pleasant and very gentlemanlike to her aunt and uncle. Elizabeth feels her own attitudes changing toward Darcy, and as she dares to hope their relationship can be reconciled, she gets news from Jane that Lydia has run off with Wickham. The two have not married, which brings disgrace to the entire Bennet family.
Elizabeth tearfully tells Darcy, and afterward, she feels that it is impossible for him to ever be connected with her family. She returns home to wait for news while her father and uncle go to London and search for Lydia and Wickham. Weeks pass, and her father returns home empty handed. During the same time, Collins realizes Charlotte is a zombie, beheads her and burns her body before hanging himself.
The family is overjoyed when they receive a letter from Elizabeth’s uncle, telling them that Lydia and Wickham have been found and are to be married. Wickham has been in a carriage accident and is now an incontinent quadriplegic. After the wedding, the couple visits the Bennets before leaving to Ireland where Wickham will join a seminary for the lame. Elizabeth learns that Darcy discovered the pair in London and persuaded Wickham to marry Lydia with the promise of paying off his numerous debts and providing the couple with a living, hence saving the Bennet family from ruin. Darcy also severely beat Wickham, resulting in his current condition, not a carriage accident as everyone was led to believe.
Darcy and Bingley return to the county where Bingley resumes his courtship of Jane. Elizabeth, now very much in love with Darcy, hopes he will court her as well, but the two are nervous around each other, and Darcy leaves and returns to Pemberley. Eventually, Bingley proposes to Jane, and she joyfully accepts.
Elizabeth receives an unexpected visit from Lady Catherine who is furious at hearing rumors that Elizabeth and Darcy are to be engaged. Lady Catherine believes Darcy and her daughter Anne should marry, and so she challenges Elizabeth to a fight to the death. Lady Catherine is a fearsome warrior, and while the two are well-matched, Elizabeth bests her and kills Lady Catherine’s ninjas in the process. Elizabeth spares Lady Catherine’s life, knowing that Darcy would be angry and sad if she is killed.
Darcy is touched by Elizabeth’s kindness and returns to Longbourn, telling her he still loves her and wants to marry her. While walking, Darcy and Elizabeth encounter a hoard of zombies and, for the first time, fight together. The two are married and begin a happy future together, for as long as the ever-present threat of zombie apocalypse allows it.