"For reliable information, apply to a lawyer, a barber, or a prostitute," suggests that trustworthy or dependable sources are scarce or unconventional. The narrator admits they haven't discovered who paid the captain yet, implying a mystery or hidden motive behind the captain’s actions.
Margaret believes that eventually, the informant will find out the truth about the payment. Both characters share a serious tone, indicating the importance of uncovering this secret in their context or story, highlighting themes of intrigue and the search for truth.