Tongues of serpents

The dragon Temeraire and Captain Will Laurence, having been convicted of treason and sent to the prison colony at New South Wales, is asked by Captain Bligh to help him regain his office, which was taken away from him when the government was overthrown, and, as the dragon and the rider journey through the forbidding Blue Mountains, they struggle to protect the two remaining dragon eggs they carry with them and find the missing third.