SPOILER. . .
Daphne catches Bramwell and Catherine in an intimate embrace in the gazebo, admitting their love for each other.
And later. . .
Morgan witnesses his wife Catherine and her lover, Bramwell, in the gazebo, discussing THEIR child, which resulted from their one night of passion together before Catherine married Morgan. This sends Morgan into a spiral of madness that causes him to attempt to kill the faithless couple.
Love, Robin