An Invitation for Sometime Between Earliest Times to 700 CE

From my Lifestyles in Early South Asia: A Sourcebook for Time Travelers, which I hope to launch soon!

      It's your lucky day. You're just minding your own business in your favorite bookshop when a group of people stumble in from the street. Sort-of. You're rather certain they weren't there, on the street, a moment earlier.
     They look exhausted and not terribly clean. They talk in what sounds like a couple dozen languages, and you see clay-encrusted pickaxes sticking out of a couple of their knapsacks, and one of them is carefully putting away a stack of narrow leaves covered with impossibly tiny writing. Another has a set of crude little bowls in tow, and another a notebook open to some sketches of – are those toys? and is that a musical instrument? Oh, god, is that a lice comb? Then you smell something very odd and notice a collection of spices, maybe, tumbling out of one of their pockets. Some of them start toward the linguistics section, others toward the history, others ­–
     I should have mentioned that you're minding your own business in your favorite bookshop because you happen to own your favorite bookshop. So unfortunately it falls to you to mention that the pickaxes are frightening your other customers.
     "Oh, sorry. We should have realized. Smyth, can you take these out?"
     "Certainly."
     You're just wondering if you also want to mention you'd rather not have Odd Spice all over your floor, when one of them turns to you. "Would you mind filling us in, dear, on what year it is?"
     He seems terribly relieved when he hears your answer.
*
     It's your first encounter (I presume) with time travelers. They explain, naturally only after they've fetched you a cup of tea "to soothe your nerves, dear," "Our speciality is meeting people, seeing how they lived – most of those unfortunate people no one's met for millennia, think of that." You're assured that every effort is made for reports to be accurate, as reliable as possible. "Though no one believes us when we tell them we're time travelers," one mentions sadly.
     For some reason, you are inclined to suspend disbelief for a while. One explains that their speciality is South Asia, and they pull out a tattered map…and someone else explains they go to any time, as long as it's around 700 CE at the latest. Others go later, but they like the really old stuff.
      Then they go browse in your shop, and you tend to some other customers as you think over what they've said.
      An hour or so later, as they're purchasing a stack of maps and books, using wads of modern currency that seem to have been sewn into their clothes, they ask you if you'd like to join them. Strictly part-time, of course; you have a life. This is when you realize this has been your lucky day, and of course you decide to join them at least for a short tour.
However, for some reason you feel a bit suspicious and ask them how the vacancy arose on their team. You could swear someone murmurs something about human sacrifice, religion and all, but you shrug it off as a problem with their accent....
     ...Over dinner, the time travelers you met at your bookshop get you started on your first expedition. They introduce you to their newspaper where they gain their information on places to stay on their travels pre-twenty-first-century, and they advise you to eat at various restaurants that specialize in historical cuisine in order to get the full, um, flavor of life in various eras.
      Then, at the end of dinner, they present you with Lifestyles in Early South Asia: A Sourcebook for Time Travelers, which includes menu cards, some articles published recently in their newspaper, and other documents that some of them wrote about their travels, including some fictionalization, in with editorial notes and (mostly, to tie it all together) an attempt by a modern-day writer to tell the story of how humans have lived in South Asia....