Why is Tellson's Bank the natural gathering place of the emigres and what is the "Loadstone" for Charles Darnay? This can be found in Chapter 24 of Book 2 from A Tale of Two Cities.
Tellson's Bank is a natural spot for the emigres' to gather because it has branches in both France and England, providing a bridge between the two. Many of the French aristocracy have emigrated to England, and so it serves as a message center. Also, its financial stability provides them a place where they can keep funds, away from the revolutionaries. They desire to be close to these funds should they need them to escape the country. Tellson's serves as a fortress for the aristocracy, just as the Bastille serves as a prison.
Darnay's loadstone would have to be the Manette household. Besides Lucie, Dr. Manette also provides him a sense of security and belonging.