investigating all the seemingly unrelated mysteries leads to some connections. spike hudson, leader of the hudson gang, uses a house near bayport as a hideout—a house which has vicious-looking stuffed animals hidden around it at strategic points to discourage unwanted snooping. and the "help -- hudson" message, though initially thought to be from or about spike hudson, seems to instead be from a group of stranded researchers trapped somewhere on the isolated coast of hudson's bay...near to where spike hudson has another hideout. soon, the hardy boys are travelling by plane to the fictional white bear river in remote northern ontario, canada (references in the book place it most likely somewhere near moosonee and moose factory) to try to solve the thefts, rescue the researchers, and break up the hudson gang.