I "rescued" some stranded pax in Calcutta a few years ago. They had paxed DXB/CCU and were supposed to be continuing via SIN to BWN but there was a problem (cant remember what) and we lobbed in to CCU to pick them up. Only snag was that we were operating BWN/LHR via AUH! Pax ended up going to AUH with us (after an unplanned nighstop CCU) before eventually getting a flight to BWN. Took them 48 hours to get back (almost) where they started from!