Same evening check in request- scam?

[Neah8]

I had a booking for a few months for 5 nights at a good rate. Guest cancels today (same day of check in), 8pm. He seems perfectly fine with it.  Doesn't ask for a refund. Doesn't get one. 10 minutes later I get a request for same day check in (tonight) by someone else for same dates and she says she's coming for "work" with her assistant. It all seems fishy and too much of a coincidence. I decline the last minute booking. 
scam? Sex work? My instincts say it was a party or sex work but could the cancellation and new request be related in some way?

[Mike-And-Jane0]

@Neah8 Yes they are clearly related - One guest cancelled, freeing up your calendar and another booked as a result. I doubt there is much more to it than that.

[Shelley159]

Hi @Neah8 

I agree with you and with @Mike-And-Jane0 here. On the one hand, it seems unusual that someone would book a 5-night stay so extremely last-minute (last-minute bookings are usually for one night, in my experience, and the time of night was quite late). The exact booking dates are also odd. But it's difficult to see how this can benefit the guests in some sinister way. If I understand correctly, they would have paid double for the same nights (maybe the first booking was at a higher rate and you may have applied a last-minute discount by the time the second booking came through, but I'm still not following how this would benefit them as there was no refund). I understand why you declined, but maybe we need a host who has seen this before to understand what it could possibly be. It would make sense to me if it were a company sending a co-worker on the business trip instead of the original guest, but then one would expect them to simply let you know about the change.