From the introduction:
You are the owner of the Lady Rita, a creaky diesel riverboat based in Manaus. Your present trip is a supply run to the Haswell Expedition. You also have a package for Haswell himself, which you intend to hand-deliver because he hasn’t paid you for the last run of supplies yet. He owes you money that you badly need.
In Whom We Trust was originally written for the Call of Cthulhu tournament at Convulsion ’96. Since then it has been played a number of times and suffered a variety of edits.
In Whom We Trust was also used as the RPGA tournament scenario at GenconUK 2001.