Like the mariner in the old story, the winds and streams had driven him within the influence of the Loadstone Rock, and it was drawing him to itself, and he must go.
Dickens is referencing Coleridge's story or rather poem, "The Rime of the Ancient Mariner" which was one of the first 'romantic' poems I read by English poets of the 1700s. It's about a mariner who is riddled with guilt and haunted by his own actions. It is cool to see Dickens use this to explain how Darnay is feeling at this moment.
