Ann and Arthur Trevelyan were born and raised in Calcutta, the major administrative centre for East India, to a British-born mid-ranking official in the Indian civil service and his India-born ethnically British wife, daughter of a Major in the Royal Indian Army. They were principally schooled in India alongside multinational and ethnically Indian classmates who were similarly being educated to enter the professions like law, medicine, accountancy, and public service. Although they were both sent to Britain for three years of schooling between the ages of 13 and 16, each see themselves as Indian with little in common with the 'mother country'. As much as they complain about the sultry Calcutta climate, they think Britain is a dreary, industrial backwater. All the action, as they perceive it, is happening in the outposts of empire.
Their friends, Christina and Neville Mortimer, are the children of a non-conformist military chaplain who served in the Royal Indian army for 20 years before retiring to his native Wales to become vicar of a small country church. The two sets of siblings met as young children and became fast friends even though they often go without seeing each other for years at a time. As the game opens, they have been reunited only a few days after almost three years apart.
Whereas Ann and Arthur are relatively adventurous and outgoing, Christina (or Tee, as Ann calls her) and Neville are reserved and cautious. Christina trained as a nurse and is currently on a holiday before she is due to start working at the biggest hospital in Calcutta. Neville is something of a mechanical genius who finds people wearying and hates having his time structured by university lectures or job commitments. For the last few years, he has made a living of sorts as an itinerant fixer and repairer of all sorts of mechanical devices, from watches to steam cars. He finds machines much easier to deal with than people.
Ann and Arthur are fiercely competitive with each other. Although Ann's formal education skewed towards preparing her for a traditionally feminine career, she was ruthless in getting Arthur to share what he learnt in school. In addition, either sibling may be a keen archer, fencer, athlete, or martial artist, according to player choice.
As the youngest of the four, Arthur believes he is not taken seriously, not appreciating that this may be the result of him affecting not to treat anything around him seriously. Arthur secretly admires his sister's strength of will and determination and is somewhat in awe of her – a respect that he masks with a studied care-free attitude (in contrast to her own fierce focus) and a sarcastic wit that frequently gets him into trouble and is sometimes more wounding than he intends.