Downton Abbey becomes a convalescent home during World War I. Lady Mary Crawley, an eligible but proud aristocrat, navigates romantic entanglements. Her former suitor, Matthew Crawley, a lawyer and heir, returns from the front, but is engaged to Lavinia Swire. Meanwhile, Mr. Bates, Lord Grantham's valet, faces blackmail from his estranged wife, Vera.

The war effort impacts the household, with Lady Sybil training as a nurse and Edith assisting patients. A major turning point occurs when William Mason, a footman, marries Daisy Mason before dying from war injuries. Later, Vera Bates is found dead, clearing the way for Mr. Bates' potential freedom. Miraculously, Matthew Crawley regains the use of his legs.

As the war ends, the convalescent home closes. Despite a brief scare with a soldier claiming to be Patrick Gordon, the season concludes with Matthew proposing to Mary, and she accepts, just as Lavinia Swire tragically dies from the Spanish Flu, leaving Matthew free to marry Mary.

Season 2 of Downton Abbey covers episodes 1-8. Here's everything that happened:

Season 2, Episode 1: Episode 1 - Set during WWI in late 1916, Downton Abbey prepares to become a convalescent home. Lady Sybil begins training as a nurse, while Edith learns to drive a tractor for the war effort. Mr. Bates is blackmailed by his estranged wife, Vera, and forced to leave Downton, devastating Anna. Matthew returns from the front, but to Mary's heartbreak, he is engaged to Lavinia Swire. The episode concludes with Thomas intentionally wounding himself to escape the trenches.

Season 2, Episode 2: Episode 2 - Downton Abbey is converted into a convalescent home, leading to a power struggle between Cora and Isobel. Thomas, aided by O'Brien, takes charge of the medical staff. Anna is reunited with Bates, rekindling their romance. William is called to war, and Mrs. Patmore forces Daisy to accept his marriage proposal. Lady Edith finds purpose assisting the patients, while Lieutenant Courtenay tragically commits suicide. The episode concludes with Sir Richard Carlisle proposing to Mary.

Season 2, Episode 3: Episode 3 - Downton Abbey's convalescent role sparks tension between Cora and Isobel. Matthew and William are reported missing.

Season 2, Episode 4: Episode 4 - Downton Abbey faces wartime tragedy. William, fatally wounded protecting Matthew, marries Daisy before his death. Matthew is severely injured, learning he is paralyzed and unable to have children. Vera Bates's blackmail forces Mary into an engagement with Sir Richard Carlisle. The episode concludes with William's passing and Matthew

Season 2, Episode 5: Episode 5 - Matthew and William are gravely wounded in the Battle of Amiens. William is brought to Downton, where he marries Daisy before succumbing to his injuries. Matthew learns he is paralyzed and breaks off his engagement to Lavinia. Meanwhile, Vera Bates attempts to expose Lady Mary's past scandal, but Mary confesses to Sir Richard Carlisle, who then buys Vera's silence and announces their engagement. A mysterious, disfigured soldier also arrives, claiming to be Patrick Gordon, the presumed-dead heir.

Season 2, Episode 6: Episode 6 - A disfigured soldier claiming to be Patrick Crawley causes a stir before departing, his identity ambiguous. Ethel learns Major Bryant has died. Bates' divorce is jeopardized, and Vera Bates is found dead. The war ends, and Matthew miraculously regains the use of his legs, offering new hope.

Season 2, Episode 7: Episode 7 - As the convalescent home closes, Downton returns to normal. Matthew miraculously regains the ability to walk, shocking everyone. Sybil attempts to elope with Branson, but Mary and Edith intervene. Sir Richard's manipulative tactics are exposed, causing Carson to refuse his employment. Bates is found guilty of murder. The episode concludes with Matthew proposing to Mary, and she accepts.

Season 2, Episode 8: Episode 8 - The Spanish Flu ravages Downton, delaying Matthew and Lavinia's wedding. Lady Sybil announces her engagement to Tom Branson, angering Lord Grantham. After Matthew and Mary share a kiss, Lavinia Swire tragically dies from the flu. Anna and Bates marry, but their joy is cut short when Bates is arrested for murder.