Dead Poets Society ending explained

What happens

After Neil's suicide, the school blames Keating and fires him. As he leaves, Todd stands on his desk and says "O Captain! My Captain!", and other boys follow. Keating's lessons survived the school's pressure, though not without cost.

The last image

Boys stand on their desks as Keating, moved and grateful, watches them from the doorway.

What it says

The ending says that a teacher can open a door but cannot control what lies beyond it. The film sides with free thought, yet the desks celebrate loyalty while leaving open the price paid, especially by Neil.