Charlotte and Sidney find themselves at loggerheads but must work together in an attempt to rescue Miss Lambe. Tom tries to save Sanditon and his marriage, while Edward and Clara enter into a scandalous pact to finally get their hands on Lady Denham's inheritance.

As the Sanditon summer regatta approaches, Sidney wrestles with his feelings towards an old flame and Young Stringer reveals his feelings to Charlotte. With Lady Denham at death's door, the tensions between Edward, Clara and Esther finally come to a head - with surprising consequences.

On the night of the Midsummer Ball, romantic interests are finally resolved. However, the fate of Sanditon is in the balance when events conspire to leave Charlotte and the Parker family facing down impossible choices. Series finale.