Baptista Trewthen is the daughter of a small farmer in St Maria's, one of the Isles of Lyonesse.
During the Easter holidays she accepts a marriage proposal by Mr David Heddegan, a rich man from Giant's Town who is at least 20 years older than herself.
On a Saturday at the end of July, four days before her wedding, she misses the steamboat from Pen-zephyr to St Mary's, and the next boat is only on Tuesday.
One day later Baptista marries Mr Heddegan as planned, without telling anyone about the brief interlude on the mainland.
They spend their wedding night at an inn in Pen-zephyr, accidentally the same place where Charles' corpse is kept.